Online image editors

Fotoflexer

http://fotoflexer.com/
Crop; resize; rotate; flip; hue/saturation/lightness; contrast; various Photoshop-like effects
fotoflexer.jpg

Photoshop Express

http://www.photoshop.com/express
Requires free registration; 2 GB storage; crop; rotate; resize; auto correct; exposure correction; red-eye removal; retouching; saturation; white balance; sharpen; colour correction; various other effects
photoshop_express.jpg

Picnik

http://www.picnik.com/
"Auto-fix"; rotate; crop; resize; exposure correction; colour correction; sharpen; red-eye correction

picnik.jpg

Splashup

http://www.splashup.com/
Requires free registration; Flash-based interface; resize; crop; layers; flip; sharpen; blur; colour effects; special effects
splashup.jpg

Snipshot

http://snipshot.com/
Resize; crop; enhancement features; exposure, contrast, saturation, hue and sharpness correction; rotate; greyscale
snipshot.jpg

Source:
21 Free online photo editing tools - http://www.10000words.net/2008/07/21-free-online-photo-editing-tools.html