birdeye - Google Code

birdeye - Google Code
This looks promising, and they're implementing (implemented?) a version of this:

• Christopher Homan and Andrew Pavlo and Jonathan Schull, "Smoother transitions between breadth-first-spanning-tree-based drawings", Proceedings of Graph Drawing, 14th International Symposium, GD 2006, Karlsruhe, Germany, September 18-20, 2006. [PDF]
• and there's video here and here ....