You ever find out about something that's been right under your nose, and you just missed it? I've known about Paint.Net forever. It's a great little graphics program written in Microsoft's .Net platform. Sort of a replacement for Paint, right? I get it.
I didn't get it.
Think a little closer to Photoshop. It turns out that Paint.Net has some pretty sophisticated capabilities hidden in there, including the biggie - plugin support. There's an active community site with tutorials, tons of downloadable plugins, and more. I downloaded some of these plugins and played with them a bit, and there's lots, lots more here than I'd been aware of. If you don't already have a high-end graphics package, this is worth checking out.