Lightworks is a video editing and composing applications I found last year just before Christmas. It has a pretty robust free version. The timeline functions are a little tricky to get used to, but seem to make sense the longer I messed around with it. Still in development, it's missing a few things such as the ability to add text within the editor and there's a small bug when rendering movies to 16:9. It seems to render just fine, but something in the file tells players to play it back at a 4:3 ratio.
This is definitely something to keep an eye on.
Vectorian Giotto is a flash animation and rendering software very, very similar to Adobe Flash. In fact, if you have used Adobe Flash at all, you will find this application strikingly familiar. I found this program last Christmas when my brother asked me about a free program to create flash banners in. Unfortunately, further development for this program was discontinued several years ago, and if you've clicked on the link, you'll notice the web page for it expired just last month.
I bet if you want to play around with it, a quick Google search will bring up a download version somewhere. It functions with AS2.
Krita is a free painting program I found recently. Originally developed for Linux, it's gaining popularity for several other OS's, including Windows. What I am impressed with this application is how much of it's design has been influenced by digital painters.
It features an actual, literal symmetry painting feature. Unlike Corel Painter or Sketchbook Pro, it not only mirrors a brush's stroke, but also the brush's dab. -So yeah, very literal symmetry when painting. (I can't figure out why those other companies couldn't figure that out! Doh!)
It also has some pretty crazy brushes which borrow from what Alchemy and DeviantArt's Muro can do. If you are looking for a pretty cool application to brainstorm visual ideas, etc, I would highly recommend you download this and give it a try.