I tried the beta version of SparkleShare. It wants to become a dropbox alternative, but it's open source and runs on top of git -which is really cool.
Here is a video of how it looks like.
This is a very promising project. And if it takes off, I can see bucket3 getting the user friendly file distribution mechanism it needs to really make sense.
Go to http://www.bomahy.nl/hylke/blog/sparkleshare-02-beta-1-for-linux/ to get the beta code.