Recently, Andy Adamatzky and I have shown that the plasmodium of Physarum polycephalum can compute a map of the Canadian highway system fairly accurately. Andy, who is based in Bristol, U.K., is well known for his work with nature-inspired unconventional computer models, such as reaction-diffusion computers and cellular automata.
If you are curious about all this, please read the details of our result:
http://research.cs.queensu.ca/home/akl/NaturalComputing/PhysarumCanada.pdf
and watch a video of our experiment:
http://www.youtube.com/watch?v=n4jRr7YAzfI
Cheers,
Selim