I'll be happy to see a fire-sharing app with an easy and useable interface that lets you share only with friends. The other options (IRC, IM programs, setting up your own torrents, FTP) are all a bit flakey and hard to use for noobies.
It seems to have fallen off the web, however it can still be found in Google's cache.
It's free for personal use as long as you indicate you used the software to create the image. Unfortunately it only accepts JPG as input.
Updated with better quality source images.