If you're getting grass stuck in your mower, or you're just tired of cleaning the blades after you've done all your yard work, the solution might actually be in your kitchen. According to AOL's DIY Life blog, cooking spray is a simple method of keeping the cut grass off the blades:
Photo remixed from an original by jeffedoe
Mowing the lawn easy compared to the dreary task of removing stuck grass from a lawnmower's blades. To keep grass clippings from sticking, spray the mower's blades and undercarriage with cooking spray before you begin cutting the grass.
Seems like a pretty good solution that could end up saving you a lot of time.
Cooking Spray - Unusual Uses [DIY Life]