I've never been big on anything "online" editing and I hate to say it, but certainly not that impressed with anything I've ever seen in terms of online image editors, until I FOUND PICNIK.
Picnik is a fast and simple way to upload photos in a jif and edit them even easier.
Keep the website window open for the fast quick edits like Resizing, Rotating, even AutoFix and
cool things like Emailing Photos, uploading to Flickr, and saving to a library.

Best part is you don't even have to sign for anything. Just Upload and go.
Photo adjustments are PRACTICAL AND they TAKE JUST SECONDS.
Even faster than PHOTOSHOP.
Make no mistake. I'm not big on online editors but PicNik is like a Walk in the Park.

Go testdrive it at www.picnik.com

For a list of more online photo editors, go to:
http://sixrevisions.com/