the PSP is about the same size as a DS. I believe its a little longer, but not much. I don't think the PSP will fit comfortably in a pocket. I often don't carry my DS in my pocket because of its size, so I can't see carrying a PSP in one, especially when the PSP is probably a bit more fragile. In fact, if I do get a PSP, I'll probably buy a very sturdy case to carry it in to prevent the screen and the hardware itself from getting all scuffed and scratched.