I say this with affection: StumbleUpon is one of the great time wasters of the Web. You probably know the concept: You install the StumbleUpon toolbar in your browser, click the button and you're taken to a random web page that was recommended by another Stumbler. Once you get started, you can pretty much count on at least an hour being vacuumed from your life. You can no more click that button just once than you can eat just one chocolate chip.
Now the folks at StumbleUpon (who are denying rumors that they're being bought by eBay) have launched a new way of abducting your afternoon. Called StumbleThru, the new feature lets you restrict your random Web hopping to one site. Choices include YouTube, CNN, Flickr, Wikipedia and more. You can get the new feature by updating your Firefox or IE toolbar extention or you can go here if you'd like to try it without loading the toolbar. I'd have posted this item this morning if they hadn't added The Onion to the list. Damn you, StumbleUpon!