I got a pitch from Web site discovery service Streakr this morning. It sounded somewhat interesting, if derivative: It's a service that lets you find sites you like through a toolbar plug-in for your browser. You mark sites you like (thumbs-up or -down), and it does a better job of finding the next one for you. Sound familiar?
The site does have some usability twists. If you want to find other people who like what you like, you can type in tags, and as you type, list of of people that have entered those tags in the profiles will narrow.
It's not nearly enough to pull me away from StumbleUpon. I'm not saying there's no room for a StumbleUpon competitor in the market (StumbleUpon was acquired by eBay; perhaps Streakr's founders are looking for similar action from Google, AOL, or Microsoft), but it's always my hope that when a new product comes out that apes an existing service's functionality, it adds more than a tweak or two to the concept. See my take on Icebrrg, the Wufoo copycat, for a bad example of this. On the other hand, Pownce, while it duplicates much of Twitter's functionality, has much better message threading and a clean UI. It extends on Twitter. Since I hardly think StumbleUpon is the last, best word in social browsing, its new competitors, like Streakr, should do more to add to the concept.