Picmeleo: a very pretty, but not functionally fantastic, embeddable Web 2.0 photo editor
Picmeleo, if you're wondering, is an online photo editor. It's actually pretty good -- not world-changing, nor any better functionally than Picnik -- but it is embeddable. The Picmeleo site isn't actually for editing photos: it's for signing up. You then embed the editor on your own website, blog, or whatever -- and it works! It works well.
Some gripes about the editor though: no mouse scroll (I love mouse scroll in Google/Bing Maps!), no double click zoom (though page up/down and the arrows work OK), you can't drag the menus around, and most importantly, it's Flash -- Flash, in a rounded-corner pop-up box. Sorry... I just can't get over it.
Give it a go though -- the embeddability might be just what you're looking for.