Tweetdeck, one of the better Twitter desktop clients, has now been release for the iPhone.
I used to use Tweetdeck, until Tweetie came out for the Mac (a native client). However on any other non-apple platform I recommend Tweetdeck or DestroyTwitter (both Adobe Air apps) to my friends.
In the last 24 hours Kevin Rose, of Digg fame, blogged about getting hold of the Tweetdeck beta. Since then the blogosphere has gone mad about it. Mashable reports that the app is now live in the Apple appstore.
You can get it for free from the App Store.