Snipshot
There are many free online photo editors out there but Snipshot is one of the most popular, which is no surprise as it's a snap to use.
It takes just a few clicks to size or touch up all types of images thanks to an easy-to-understand interface that even the least technically savvy will appreciate. The program has many interesting little features and, best of all, it is well integrated with Firefox (you'll need an extension) and Flickr.
You don't even need to sign up but if you want to edit photos that are greater than 10MB, you'll need to become a paying member of Snipshot Pro. Snipshot PRO also allows you to edit RAW photos and add special effects to your images, but there is absolutely no obligation to sign up.
Hard to believe it's free
GimpShop
Another feature-rich free graphics program option!
Perfect your photos
PXN8
Great tool that lets you retouch and modify images easily.