This question doesn't pertain to game development, but it does have to do with using Maya, and I'm sorry but I can't find an answer anywhere else and I thought I might give this a try. (I'm using Maya 6.5 Unlimited). What I have is a path on top of a cube with grass on it. The path is curved, and I want the grass to grow around the path. But the grass grows up through the top of the path. Is there any way to make the grass grow only around the path with collision detection or something? Thanks in advance.

I don't understand exactly what you're asking to do... can you show me a screenshot?

Also, for software specific questions, www.cgtalk.com is probably a much better resource (or Alias forums on their website).

Here is a link to the screen shot
http://www.geocities.com/shipperinc/messup.bmp
Is there any way to stop the grass particles from coming through the sidewalk and to make them just grow around it?

Are you using Maya Fur or PaintFX?
One way is to just get rid of the geometry of the grass below the sidewalk, so it can't grow.
For fur, you can paint 100% bald below the sidewalk.
For PaintFX, just don't place them below the sidewalk.
My suggestion, though, is to just delete the geometry below the sidewalk. This'll be the most efficient and bug-free. You'll also be able to paint in a higher density at the edges of the path, emulating nature, while getting hard edges and exact values painted on a surface is really a pain to do (the need to do so is eliminated by deleting the geometry).