Picnik Online Photo Editing
So, isn’t it perfect if there’s an online photo editing tool which doesn’t require any software installation?
Yes, there is. Picnik is the answer.
Picnik allows us to load a picture, apply some common photo fixing and tweaking, and save the edited copy.
Select Photos

You can select or open a photo in Picnik from Flickr, your computer, a website link, Yahoo search, Flickr search and even WebCam. I believe these options are comprehensive enough to cater all general needs.
Photo Tweaking

Currently, the photo editing features available are auto-fix, rotate, crop, resize, exposure adjustment, colors adjustment, sharpen and red-eye reduction.
I’ve tried out the auto-fix feature, and it works well automatically fixing the color of an overcastted photo. This is one of the common and frequently used fixes.
In terms of special effects, you can also easily convert a picture into black and white, sepia tone, boosted colors, and etc. More effects are coming up soon.
Save and Share

Once you’ve done with your editing, you may save the photo to Flickr or computer, email the photo, or print it out.
Though Picnik doesn’t offer comprehensive set of photo tweaking options, but it succeeded in making the interface simple, getting the job done in a few clicks, while offering commonly needed features. Best of all, no software installation is required. From my experience, the processing is satisfyingly fast!
* thanks to Kit Yee for sharing this site with me *