Has anyone ever tried grit paper for birds in their cages?  I thought of putting it on part of the bottom level and maybe it would file down their nails a little.  Does it sound like it may work?  I've heard putting a brick under the water bottle but thought this may work also if they don't tear it up.  Any suggestions?

Sand/grit paper actually isn't safe for birds. It hurts their feet, and most birds that people keep don't need grit (it can actually impact their crop and kill them).

I wouldn't use them. I keep a brick in my cage.

I thought that my girls were the only ones that liked rocks. I used to have a rock in there and then I upgraded to a brick! lol. I swear they'll push each other off of it just to be able to sit on it and stare at you. 

Odd request- but, can people post pictures of their rocks?!? I have a brick and a couple rocks, but they're all pretty smooth. I just threw them in the cage to keep things cool. I imagine to keep nails filed a bit, you folks are using grittier bricks and rocks? Pix plz!