David Anderson, a long time member of the Dallas Personal Robotics Group, did an interesting presentation recently in which he distills down what he's learned about building subsumption based mobile robots over the years. The video is a bit long but well-worth your time if you're interested in intelligent robots. David provides some additional notes that link to video of specific examples. And don't forget to check out David's "my robots" webpage for more photos and details on his robots.