There appears to be an iPhone version of Jumpman out now, and it appears to totally suck. That's another issue with video games, they really are designed for particular screen sizes and input hardware, which makes it hard to play old, classic games, even with emulation, without that hardware. (I actually have one of those NES controllers that are modified for USB so I can play old NES games through emulation the "right" way. But I never actually do this.)