Gallery
From Synfig Studio :: Documentation
You are encouraged to distribute your source files (.sif and so on) so others can learn from your work. Obviously this is only if you have permission to distribute all of it. You can find more videos and images on synfig.com, youtube, flickr, google video, maybe google images and maybe on some blogs or articles about synfig.
"Eyes" animation (mp4) by Anders K. Madsen
Download "Eyes" source file
An example of what the plant layer could do if it wasn't broken ;)
A synfig version of the "Wind" Windows XP wallpaper. Animated version.
Synfig cat, by Rore. With a heavy use of width-ducks on blines.
Tux, with a Synfig logo. SIF file. (With acknowledgment to Larry Ewing and the Gimp.)