Our first is related to the still-born Snap.com. It's called WebSnapr, and I'm going to try it here on the blog for a while. Preview thumbnails of pages that I link to will show up inside of this preview bubble:
Second, we have the Y-Combinator funded Snipshot. This is a primitive image editing program that runs completely in the web browser.
Lastly, and perhaps the most impressive to readers of this blog, I want to mention Yahoo Pipes.