to also touch on what omega ra said......
cooked roms are exactly what he mentioned. it is a custom os install that takes away the bloatware and installs nice features, frees up memory, and unlocks things like the gps feature that our phones have.
now to get the roms, you'll need the unofficial rom, then go with one of the roms that the cooks in here have put together in their kitchen, and you'll be all set.
if there's anything else, please don't hesitate to ask. someone is always around to help. that's what's so great about this site!
happy reading and enjoy.