Well, looks like Adobe has pulled another one out of the bag with Photoshop Express, a web-based Flash application that lets you colour adjust, retouch and add effects to your photographs without installing anything.
The interface is really easy to use and it looks as though this is aimed at your average non-designer web user, with easily navigated albums and photo editing interface.
This is really setting a new benchmark in rich web apps. The beta is available for a test drive now.
Wow, that looks really cool.