Riverfold Software — my friend Manton Reece — just released Tweet Library (iTunes link) on the iPad.
It’s another Twitter client, yes — but it does a bunch that the other ones don’t. It archives your tweets and provides filters and collections. Is Twitter important to you? You may need this.
There’s a website that talks more about it — with screenshots and an intro video.
One of the cooler features: you can publish a collection of tweets to tweetlibrary.com. Lately I’ve been thinking about web-based features like that for my own software — so it will be interesting to watch tweetlibrary.com and see how it goes.