I use MeBoy for GB emulation (http://arktos.se/meboy/). Follow the directions given and use http://pcs.cruz-network.net to upload.
The only games I've played on MeBoy are the Pokemon games, assuming that they were just best for Cellphone. Now all that's needed is a link feature to trade and battle Pokemon.
Follow the directions there and use the same site I use. It should be Javagear ME, FYI.
I loaded the Sonic games (except the Drift series and Labyrinth), Ninja Gaiden, and Megaman. They're playable, but running at like 4 or 5 FPS on my SGH-A767 (gonna get an Erricson next upgrade).
Looking at the benchmarks for the emulators on my phone, I think I can just forget about Doom ME (not Doom RPG), knowing that a J2ME Doom port would make my phone explode.