Picnik offers you digital photo retouching, easy and fun. Its allows you to manipulate any image from Firefox without opening any desktop application. Includes a variety of tools (frames, effects, masks, fountains, automatic correction, …).

With this plug-in for Firefox you can, among other things, crop or resize your photos, adjust the exposure, correct levels or tone, convert to black and white or sepia, add text with different fonts, improve the focus of the image, include multiple frames, use the functions to rotate or flip, remove red eye, etc.. Also, if you create your free user account you can share pictures and win some more features.