A friend, Jeremy Penner of Glorious Trainwrecks semi-fame, pointed me to this video:
Bret Victor - Inventing on Principle from CUSEC on Vimeo.
That's some amazing UI thought right there. I love how laying out animations can me more like puppeteering if you do it right... and the rest is completely inspiring as well.
Random plug: to get the embeded code the size I wanted it I used my old Youtube Resizer -- it needs a better name, since A. it works on things other than youtube (like Vimeo here) and B. Youtube has put the same functionality into their basic "embed this" webpage, but still, the thing works pretty well.