Hi folks!
For a contest entry, I used Inkscape in conjunction with Synfig to make a 30-second animated commercial (of sorts). I did it in two days, just before the deadline, so it isn't exactly perfect, but it turned out reasonably okay. Synfig imports svg files pretty well now, so I was able to create all of my elements in Inkscape (and thus take advantage of its really nice drawing and painting abilities), then take them into Synfig for rapid (though in this case limited) animation. Here's the finished product:
http://www.youtube.com/watch?v=UY4rx7CzaDY
(If you'd like to help me win the contest, please feel free to hit the "Like" button. :D )
I used Audacity for the sound recording and Blender's Video Sequence Editor to edit everything together. Plus, it was all done on Ubuntu, so it was a complete open source project.
If there are any coders on the list who are just dying for more stuff to do (it could happen!), Synfig could really use some help as it doesn't yet have anything close to the user base that Inkscape enjoys. I hope, though, that this little contest entry shows the potential that Synfig has and, especially, what a great combo Synfig and Inkscape can be.
Cheers!
Matt Jordan