I guess this is a portent of what is to come -- most applications being on-line based. As someone pointed out -- this makes you operating system rather moot. This has huge implications on business models.
Anyway, I have just become aware of photoediting software on-line. This in includes: Adobe Photoshop Express, Picnik, and splashup. These use Flash and other techniques to let you edit your snaps on-line. While some of them are limited to minor modifications, Slashup lets you edit in layers. I have only briefly looked at them, but I am sure they will become very handy.