- Emulation (SNES/NES/GBA/Genesis/Megadrive/Dreamcast/N64) - Ok, Dreamcast barely works but the people behind it think they can get some games playable.
- Can play downloaded games
- Can convert Playstation 1 games into PSP playable titles (basically emulation again)
- Homebrew apps
- You don't need to use the UMD drive for games which increases battery life and decreases loading times substantially.
That's the main things I use mine for personally, you will however have to get a memory stick (4Gb~£20ish) and a Pandora battery though. (tenner for the latter)
Well worth it.
In this day and age i would be cautious with anything that is pirated over the net