Check these recent Gamasutra Feature, pretty good stuff on advanced pathfinding...
http://www.gamasutra.com/features/20060626/strom_01.shtml
and
http://www.stromcode.com/wiki/index.php?title=Main_Page/Articles/Genetic_Programming:_Evolving_an_Intelligent_Pathfinding_Algorithm
http://www.gamasutra.com/features/20060626/strom_01.shtml
and
http://www.stromcode.com/wiki/index.php?title=Main_Page/Articles/Genetic_Programming:_Evolving_an_Intelligent_Pathfinding_Algorithm