Pinta is a simplified image editor based on Paint.NET (and thus it uses Mono), designed to serve as an alternative to GIMP for casual users.

I've recently came across a very interesting Banshee extension which I'm sure many of you will find to be useful.

The extension is called Banshee Telepathy Extension and you can use it to share or stream music through Empathy instant messaging client with your contacts (Jabber (including GTalk) only) through a p2p protocol.