After writing the post regarding Flickr and Picnik, I came across a great post by Christian Watson on his Smiley Cat blog. In this post, Online Image Editors Compared, he compares about 13 different online photo/image editors including: Fauxto (now called Splashup), Picnik, and Snipshot. He includes a very detailed comparison chart. Here is a Snipshot screen shot.

I quote from his blog:

Thoughts and Takeaways

Overall, I was very impressed with what’s available when it comes to editing images online. By and large the tools were easy to use and had an impressive array of features.

The majority of the tools had solid basic image editing functionality — crop, resize, adjust color, brightness and so on. Some had unlimited levels of undo and redo, which was especially handy.

Some of the features available were up there with full-blown graphics tools. For example, Cellsea included the unsharp mask function for accurately adjusting sharpness.

Two of the image editors (NetImager and nexImage) allowed you to use layers to apply your changes and effects in a non-destructive way, which was a nice feature.

The tools were integrated to varying degress with online image storage services like Flickr and Photobucket. Some also enabled you to view all the images from a web page and then choose which one you wanted to edit, although apart from Cellsea, this was done via a bookmarklet.

The tools had varying capabilities when it came to uploading and saving images from/to different formats. However, between them all you could probably upload and save an image in most of the main file formats (e.g., JPG, GIF, PNG, BMP, TIFF, PDF, EPS).