It took a while, but now Twitter for iPhone is finally available in the US App Store as well. This is the official link. (check for updates if the link doesn’t work)

The application comes as a free update and has a new icon, unlike the screenshots we saw last night about the app keeping the old Tweetie icon.

Twitter for iPhone undoubtedly feels snappier and more responsive than Tweetie 2, perhaps because of the new authorization system or just because the engineers at Twitter helped Loren in refining the backend of the application. Anyway, it’s very smooth and scrolling it’s a real pleasure.

One of the most important new features is that now you can use Tweetie Twitter for iPhone even without a Twitter account: you can search, view top tweets and browse suggested users. If you want, you can signup through the application. Very cool. Also about the search, it now includes top tweets.

The old style retweets are gone. The retweet button is now included in the popular on-tweet swipe menu, but if you try to “quote” a tweet, the app won’t use the old /via syntax: you’ll simply get a quoted message.

The overall feeling is that Twitter started from the solid base of Tweetie, changed a thing or two about search and retweets and improved the engine for faster times and responsiveness. I don’t like the new icon, but that’s it.

Twitter for iPhone is a great application, being it an evolution of the Tweetie we know and love. I hope they won’t ruin things with the future updates, but in the meantime it’s safe to say that this is (again) the best client you can have right now on your iPhones.

Now let’s wait for the new Twitterrific and see what happens.