Apple released its newest update for iPhone named iPhone OS 3.1. This update, other than adding a bit more trouble for jail breaking iPhones, includes a few new goodies like
1. Genius features for app store
2. A Genius "auto mixes" play lists created based on itunes library and synced to iPhone directly without requiring the user to choose a song and then make a genius play list out of the same.
3. A ring tone store, etc
Other smaller yet useful tweaks include ability to save videos from emails and MMS to camera album, ability to paste numbers directly to phone keypad view to dial directly without adding to contacts.
All this certainly makes OS 3.1 upgrade worth the effort (or trouble for jailbreak-ed phone users)