A nice collection of Thinkpad movies covering everything from general descriptions to detailed views of components. They serve as a nice visual guide to the location of the components and as general reference.
Update: The movies from IBM have been removed.
Please see the new link to Lenovo support videos.
T40/40p, T41/41p, T42/42p, T43/43p:
Locations overview movie
Hard disk drive movie
Battery removal movie
Keyboard removal movie
Memory removal under keyboard movie
Palm rest removal movie
T60/60p, T61
Locations overview movie
Hard drive removal movie
Battery removal movie
Keyboard removal movie
Memory removal movie
Palm rest removal