StubleUpon has launched a new feature called StumbleThru which it describes as “a new way to explore personalized content within fast-growing sites such as Flickr, MySpace, Wikipedia, and YouTube ” .

The collaborative nature of Web 2.0 sites like YouTube and Wikipedia means that content is constantly being generated by millions of users,” said David Feller, Vice President, Marketing at StumbleUpon. “StumbleThru provides users the ability to skip the clutter and unearth only the best that these domains have to offer.

It basically allows users to Stumble to specific domains and you can rate the contents using the thumbs-up and thumbs down system as before . So if you want to search wikipedia, just Stumble Wikipedia . The list of supported sites include : Flickr , MySpace , Wikipedia , Youtube ,   Wordpress , The Onion , PBS , Physorg , CNN , BBC  with more to be added later .