If you're a social networking devotee, you'll love having Nambu on your iPhone (available here), since it lets you keep track of Twitter, FriendFeed, Ping.fm, and more all from one convenient app. A simple tabbed interface lets you switch between the areas and follow your updates.

This isn't the most fully featured Twitter client we've seen, but it has the advantage of being free, and-more importantly-the developer seems committed to adding new features. The latest update added a Twitter user information page, support for threaded Twitter replies, and the ability to Retweet a message. We'd love to see the ability to track Twitter trends added.

Our favorite Twitter app is still Tweetie (available here), but if you're looking for something free and you use the other social networking tools that are included, this is a strong contender.