[varunb007]

roms are the os with default programs/settings. you can get custom roms that come with different programs/settings but you need to unlock your phone first. see the htc vogue upgrades section to find out more about this.

as far as alternate os's, i haven't really looked into it much but i know there is a somewhat functional version of android (google's os) made for the touch. i heard that's pretty safe to load on to your phone.