Paint.NET 2.72
Paint.NET is a free Open Source bitmap graphics editor for Microsoft Windows that started out as a student project mentored by Microsoft staff at Washington State University. You can find the current version at its web site...
I've found it to be a capable graphics editor that starts up much more quickly than the commercial tools I've purchased. This makes it ideal, for example, for quickly cropping and resizing a photo for an article or blog.



There's an Alpha 1 release
There's an Alpha 1 release of Paint.NET 3.0. You can find it at the BetaNews FileForum: Paint.NET (Alpha) 3.0 Alpha 1