2 Player ROMs

Its awesome to be able to play ROMs on the PSP, but I've noticed that most NES and some SNES games arent nearly as fun unless your playing two-player (Contra, River City Ransom, Mario Bros, etc.) and I was wondering if there was a way to play two player on the emulators.

The emulator i use for NES is NesterJ and for SNES is snes9xTYL. On nester J, there is the ability to use a "Player 2 mic" button, but I have no idea what that is. Can anyone help me out with this? :confused:

right at the moment there are no multiplayer roms which are playable with 2 ppl