I mentioned this a while back when it was still in the works. Today, Adobe has released a version of Photoshop Express as an online web-app. I poked around with it quickly and was impressed – it's got a significant number of key features that will improve the average person's photos. Things like red-eye reduction are to be expected, but the white balancing feature is really impressive.
Also a nice touch is integration with Picasa, Photobucket, and Facebook. Strange there's no Flickr support, but that could be forthcoming.
Check it out here.