Picnik is another online image editor. Which does not need a registration and can handle images from Flickr, Picasa, webshots, photobucket, facebook and myspace.

from the website

• Fix your photos in just one click
• Use advanced controls to fine-tune your results
• Crop, resize, and rotate in real-time
• Tons of special effects, from artsy to fun
• Astoundingly fast, right in your browser
• Awesome fonts and top-quality type tool
• Basketfuls of shapes from hand-picked designers
• Works on Mac, Windows, and Linux
• No download required, nothing to install

here is the link