Released in 1996, the GB Pocket was the replacement for the old and tired, toaster-sized Gameboy.  Exactly 33% smaller and lighter, the GB pocket sported a larger, less blurry screen, 2 AAA batteries for 10 hours of gameplay, smaller power and accessories ports, and a nifty array of finishes.  Below are a few small pictures of the GBP in its various forms. I'll put some better pictures up as I find them!  I sold mine a couple months back because I needed the money, but I want it back, just because it's so small!
There were other models made as well, such as a limited clear-green, blue, ice-blue, and several custom orders available only as promotions from Japanese countries.  If you want to give me one, mail me- You think I'm joking?  Ha! (I'd like an atomic purple one though, it would match my GBC.)