Picnik.com - Online Photo Editor
You need to check out Picnik!!! This is an online photo editor that uses Flash technology to do its magic.
It has the standard photo editor tools like rotate, crop, resize, exposure control and color settings. The color settings are basic but works well enough for most general uses. However, the advanced controls include a histogram that allows the setting of shadow and highlight point separate. Very cool.
Also, Picnik is well integrated with Picasa and Flickr and from what I can tell, plays very nicely with those applications.
It really can't replace Photoshop if you are a pro, and as of the beta, you can only a single photo at a time. It is definitely good enough for the casual user that finds Photoshop too expensive and too complicated. Try it, you'll like it!