Want a geeky way to chill out after a long work day of focus, focus, focus? There are few better ways online to keep the synapses lubricated than through the semi-serendipity of social sharing service StumbleUpon.

Now you can Stumble outside of the shadow of the mega-corporate overlords at eBay - two years after Stumble founders Garrett Camp and Geoff Smith cashed out and handed their baby over to the ecommerce giant, they've come back with a team of investors and bought StumbleUpon back from eBay. It's pretty exciting.

News of the buyback comes from MG Siegler at TechCrunch, who has published the press release in full. The company blog post about the move is short but here.

Why is this such a big deal? For three reasons.

StumbleUpon is Back in the Game

Earlier this year we wrote about StumbleUpon hitting 7 million registered users, which was at the time 50% higher than most estimates of media darling Twitter's users. Twitter's numbers have shot through the roof this year, leaving StumbleUpon in the dust.

Some people told us that Twitter and Stumble are like Apples and Oranges. Both, though, are tools of discovery, sharing and social connection. They are different in some ways but similar in others. There's a special kind of magic to StumbleUpon, though, and we're very glad to see its founders back in the driver's seat. A web where Twitter and Facebook are the only social discovery games in town is a poorer web.

Some Suspicion is Mitigated

Dave Winer wrote last week that the reason everyone wants to know how Twitter is going to make money is because eventually they'll come up with something - and we as users might not like it.

There was always a similar kind of feeling with regards to StumbleUpon at eBay. Just what was eBay going to do with Stumble and was it going to be creepy? Did you really want to share your serendipitous discoveries, your likes and your dislikes, with the arguably dysfunctional eBay?

Somehow Camp and Smith, as founders, feel more trustworthy. Who knows though - last time they thought it would be a good idea to sell the company to eBay! Many innovators from the beginning of Web 2.0 quickly grew skeptical after their startups were acquired, hopefully they'll be more careful next time.

Innovation Coming Again

Remember what the last wildly innovative thing StumbleUpon did was? Adding the awesome video section of the site, we'd argue, six months before the eBay acquisition. Now that Camp and Smith are in charge again, we hope to see the same spirit of awesomeness that built Stumble in charge again. The team already says they've got "several new products and features to be released in the upcoming months."

We've got high hopes for this deal, just like we do for the rumored founder buy-back of Skype from eBay.

Founders are where the innovative juice is, often, and if a big conglomerate that buys those startups can't figure out how to make effective use of these incredibly disruptive technologies - then they should get out of the way.

StumbleUpon is one of the handful of services launched on the consumer web in the last few years that can truly be said to have significant cognitive benefits for the people who use it. Give yourself an evening to peruse and explore the web using Stumble, if you haven't. It makes the brain feel good and it's a great way to learn - through play and personalization. It's a whole lot of fun. It's not something that needed to be turned into a way to jump from eBay listing to eBay listing. Stumble is smart, it's useful and we're very happy to see it independent again.