I've just been messing about with the iPhone update. Quite a few of the social network software facilities now run from the aps menu on the phone and there's also some clever ways to do things like remote control of iTunes, which is now built into the new iTunes 7. I've added twitterific, newsgator and a few other bits and pieces from the aps menu. All free software uploads. Not bad for a free upgrade.
Oh and I couldn't resist Band which is a virtual band and could keep me amused on the plane tomorrow.