I know that I have blogged about painting countertops in the past, but this is a little different. My previous suggestion was to use melamine paint (which I have personally used and it does work great!). This time I am suggesting that you can buy a kit that results in a natural stone finish.
I recently watched an episode of House and Home Online TV where they made over a table-top with the Rust-Oleum Countertop Transformations kit. I found the kit (which is available in 5 different stone finishes) at a big box store for $50 and after 5 easy steps (sand, roll, spread, smooth and seal)- viola!
Before (P.S. these pics are not from my house!)