Digieffects has video tutorials for its new Camera Mapper AE filter, mentioned earlier in New AE filters Camera Mapper and Mojo. There's an intro, plus tutorials by Matt Silverman and Mark Christiansen. They also posted a short comparison with the Photoshop Extended to After Effects format Vanishing Point Exchange (AE Help has more).
Toolfarm later posted the latest one by Mark Christiansen:
By the way, Motionworks has a video explaining Photoshop Extended: A workflow with After Effects.