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A blade including a body having a leading edge, a trailing edge, a surface point of maximum camber, and a low pressure surface extending between the leading edge and the trailing edge. The body further includes a high pressure surface extending between the leading edge and the trailing edge on an op

A blade including a body having a leading edge, a trailing edge, a surface point of maximum camber, and a low pressure surface extending between the leading edge and the trailing edge. The body further includes a high pressure surface extending between the leading edge and the trailing edge on an opposite side of the body relative to the low pressure surface. The low pressure surface includes a leading edge surface extending from the leading edge to the surface point of maximum camber. The blade further includes at least two ridges located on the leading edge surface, each ridge extending generally parallel to the leading edge.

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What is claimed is: 1. A blade comprising: a body having a leading edge, a trailing edge, a low pressure surface extending between the leading edge and the trailing edge, and a high pressure surface extending between the leading edge and the trailing edge on an opposite side of the body relative to

What is claimed is: 1. A blade comprising: a body having a leading edge, a trailing edge, a low pressure surface extending between the leading edge and the trailing edge, and a high pressure surface extending between the leading edge and the trailing edge on an opposite side of the body relative to the low pressure surface, the low pressure surface including a leading edge surface extending from the leading edge to a surface point of maximum camber; and at least two ridges located on the leading edge surface, each ridge extending generally parallel to the leading edge, wherein each ridge includes a generally upward sloping surface oriented generally parallel to a mean camber line of the body, and a generally downward sloping surface oriented generally perpendicular to the mean camber line, wherein said low pressure surface is not entirely covered by said ridges, and wherein said ridges are configured to provide noise reduction during use of said blade. 2. The blade of claim 1 wherein each is oriented generally parallel to the leading edge surface and each downward sloping surface is oriented generally perpendicular to the leading edge surface. 3. The blade of claim 1 wherein the generally upward sloping surface of each ridge terminates adjacent to an associated generally downward sloping surface. 4. The blade of claim 1 wherein the generally upward sloping surface of each ridge forms an angle of between about 70 degrees and about 110 degrees with the associated generally downward sloping surface. 5. The blade of claim 1 wherein the upward sloping surface of each ridge is longer than its associated downward sloping surface. 6. The blade of claim 1 wherein the upward sloping surface of each ridge is at least about 5 times longer than its associated downwardly sloping surface. 7. The blade of claim 1 wherein the upward sloping surface of each ridge is generally flat. 8. The blade of claim 1 wherein the body is generally airfoil shaped in cross section, and is generally smooth in areas not covered by said ridges. 9. The blade of claim 8 wherein the body has a chord and the upward sloping surface of each ridge has a length that is less than about 5% of the length of the chord. 10. The blade of claim 1 wherein the at least two ridges extend along a majority of the span of the body. 11. The blade of claim 1 wherein the blade includes at least six ridges having generally the same size and shape. 12. The blade of claim 1 wherein the ridges are unitary with the body. 13. The blade of claim 1 wherein the ridges are adhered to the body. 14. The blade of claim 1 wherein each ridge is formed at the junction of said generally upward sloping surface and said generally downwardly sloping surface. 15. The blade of claim 14 wherein each generally upward sloping and generally down sloping surface is generally flat. 16. The blade of claim 1 wherein the high pressure surface is generally flat and lacks any ridges. 17. The blade of claim 1 wherein each ridge protrudes upwardly from the blade body by a distance of less than about 0.1 inch. 18. The blade of claim 1 wherein the body is configured such that during forward movement of the blade the low pressure surface experiences a lower air pressure thereon as compared to the high pressure surface. 19. The blade of claim 1 wherein each ridge extends substantially the entire distance from a base to a tip of the body. 20. A blade comprising: a body having a leading edge, a trailing edge, a low pressure surface extending between the leading edge and the trailing edge, and a high pressure surface extending between the leading edge and the trailing edge on an opposite side of the body relative to the low pressure surface, the low pressure surface including a leading edge surface extending from the leading edge to a surface point of maximum camber; and at least two ridges located on the leading edge surface, each ridge extending generally parallel to the leading edge, wherein the ridges are adhered to the body and wherein the ridges are formed by overlapping strips of generally flat adhesive material. 21. A blade comprising: a blade body having a pair of opposed sides, each side having a leading edge portion and a trailing edge portion; and a plurality of ridges located on the leading edge portion, each ridge being defined by a junction between a generally horizontally oriented surface and a generally vertically oriented surface that is shorter than the associated generally horizontally oriented surface, wherein each ridge extends generally parallel to a leading edge of the blade, wherein said blade body is not entirely covered by said ridges, and wherein said ridges are configured to provide noise reduction during use of said blade. 22. The blade of claim 21 wherein each generally horizontally oriented surface is generally parallel to a mean camber line of the body, and wherein each generally vertically oriented surface is generally perpendicular to the mean camber line. 23. A blade comprising: a generally airfoil-shaped blade body having a pair of opposed sides, each side having a leading edge portion and a trailing edge portion; and a plurality of ridges located on the leading edge portion of only one of said opposed sides, each ridge extending generally parallel to a leading edge of the blade and being defined by a junction between a pair of generally flat surfaces of unequal length, wherein one of the generally flat surfaces is oriented generally horizontally and the other one of the generally flat surfaces is oriented generally vertically, wherein said side of said blade body having said plurality of ridges is not entirely covered by said ridges, and wherein said ridges are configured to provide noise reduction during use of said blade. 24. The blade of claim 23 wherein one of the flat surfaces is at least 5 times longer than the other generally flat surface. 25. The blade of claim 23 wherein each ridge protrudes upwardly from the blade body by a distance of less than about 0.1 inch. 26. The blade of claim 23 wherein the ridges are unitary with the blade body. 27. The blade of claim 23 wherein each ridge extends substantially the entire distance from a base to a tip of the blade body. 28. A fan comprising: a motor; a central hub configured to be rotatably driven by the motor; and a plurality of fan blades coupled to the hub, each fan blade comprising a body having a leading edge, a trailing edge, a low pressure surface extending between the leading edge and the trailing edge, and a high pressure surface extending between the leading edge and the trailing edge on an opposite side of the body relative to the low pressure surface, the low pressure surface including a leading edge surface extending from the leading edge to a surface point of maximum camber, and each fan blade including at least two ridges located on the leading edge surface, each ridge extending generally parallel to the leading edge, wherein each ridge includes a generally upward sloping surface oriented generally parallel to a mean camber line of the body, and a generally downward sloping surface oriented generally perpendicular to the mean camber line, wherein said low pressure surface is not entirely covered by said ridges, and wherein said ridges are configured to provide noise reduction during operation of said fan. 29. The fan of claim 28, wherein the fan includes at least three blades. 30. The fan of claim 28 wherein the ridges of each fan blade are unitary with the associated body. 31. The fan of claim 28 wherein each ridge of each fan blade extends generally radially substantially the entire distance from a base to a tip of associated body. 32. The fan of claim 28 wherein said fan is configured such that when said fan has four blades and is operated in air at about 1174 RPM, at a static pressure of zero, at a static efficiency of zero, at a blade pitch of between about 24 and about 25 degrees, and at a flow rate of about 22212 CFM, said fan has a sound output that is less than the sound output of a fan operated at the same conditions, but without said ridges, by at least about 3.4 decibels at an octave center band frequency of 63 Hz. 33. A fan comprising: a central hub; a motor operatively coupled to the central hub to rotatably drive the central hub; and a plurality of blades coupled to the hub and extending radially outwardly therefrom, each blade having a leading surface portion and a trailing surface portion and having at least two generally upwardly protruding ridges located on the leading edge portion, each ridge extending generally parallel to a leading edge of the blade and wherein each ridge protrudes upwardly by a distance of less than about 0.1 inch, wherein said trailing surface portion is not entirely covered by ridges, and wherein said ridges are configured to provide noise reduction during operation of said fan, wherein each ridge is formed at the junction of two generally flat surfaces, wherein one of the flat surfaces is longer than the other generally flat surface. 34. The fan of claim 33 wherein one of the flat surfaces is at least 5 times longer than the other generally flat surface. 35. The fan of claim 33 wherein each blade is generally smooth in areas not covered by said ridges.