I have previously talked about several alternatives to twitter.
FriendFeed is again, more than twitter, and it is hitting really hard.
Personally I like brightkite with the great iphone apps, but friendfeed is growing very fast!
Give it a try. You can log in with your twitter account, but you can have videos, photos, etc… You should spend some time to discober its potential.
Petty that there is no iPhone app…