Want to find out who is talking about your topic of interest on Twitter lately? Want to discover the hot topics on Twitter? Then I think you should give Tweetag, a new Twitter-based service, a try. This Belgium based service that will enable you to browse the public tweets through tags. Tagging and Twitter? How it is done? Tweetag uses a automatic tagging system, which analyzes and tags more than 200K tweets every day. These tags helps them to generate nested tag clouds so that you can easily browse through the sea of endless tweets.

On their home page, Tweetag sorts out and displays the 40 most frequent topics being discussed on Twitter. The size of each tag varies with it’s relative importance. A tag about which more people are talking about, appears big compared to a less talked about one.

You can also search with your own tags to find out who is talking about what lately! You can also use multiple tags to refine your search. You can add tags to the selection by clicking on them. A click on a tag in the “selected tags” bar will remove it from the selection.

For example, want to check tweets on Google voice search on iPhone? Just use Googe and iPhone as tags and start your search. The results are presented in four tabs - all, links, questions and replies. So, if you want to check the links posted on Twitter, related to your topic, just select the “links” tab.

Tweetag has a developer API which one can use to build cool apps and widgets based on their data. Well, this is just a beginning for Tweetag. In near future more features such as thematic tag clouds are expected to be added to the Twitter-based service. Before that, why don’t you give it a try?