i have the i730 i know you can go to the nextel site and they have some online store deal where they have ring tons and programs ect you buy them and you download them over the air. there is some download util as one of the programs that holds your buys. i believe they always stay there to re download them if you run out of space and have to delete them or phone break you can always just re download them.
http://www.nextel.com/services/javaa...tones&id3=home