ImageIM is a plugin for Gaim that lets buddies send screenshots to each other via HTTP protocol.
Users can simply click the ImageIM button, select a portion of the screen, and then send their buddy the image.
If the buddy doesn't have ImageIM, they will receive a link pointing them to the image.
Step 1: Install the latest version of Gaim
Step 2: Register a username on imageim.com
Step 3: Download either the Windows DLL or the Linux SO file. Place this in Gaim's Plugin directory. See the instructions below to build the source file.
Step 4: Once you launch Gaim, go to Preferences -> Plugins and enable ImageIM. Now select the ImageIM plugin preference and enter your username and password.
Step 5: You will now see an ImageIM button right next to the Send button in your conversation windows.