i think Virgin mobile came up with a phone and adaptor to play it like a game boy or something like that
its all about the OS... PS1 has a low spec... but all/most of its resources is dedicated to running the game
computers with WindowsXP might be able to emulate PS1 games, but it might be slower.... Windows sucks a lot of the power out...
similar thing with PocketPC... unless u want to install ur own custom OS onto ur axim...
i think emulating MAME games w/o lag would be achieved b4 PSP emulation...