For a free online image manipulation tool from a site with its own support forum:
Phixr is an online photo editor - a complete image editor that works within your web browser.
Now, let's also assume that you are at some internet cafe in a country far from home and want to email the photos you've just taken with your digital camera to your friends and family at home to share the unique experience.
There is only one problem. These photo files are huge. And a nice border around the photo would be nice, apart from some color adjustments. .... Too bad.. this computer doesn't have any image editor installed.
That's just one situation where phixr comes handy! Another typical case are computers in schools or companies where users are not able or not permitted to install software.
http://www.phixr.com/
http://www.phixr.com/account/forumlogin