for me, watching old action movies always works. the best being,
PREDATOR
if u want some real fun and can be prepared to take some time, download winamp and the g-force plugin, play a trippy drum and bass (or similar) cd and let it go!!!! especially good if your pc has a TV-out so u can watch it thru ur television.. this also allows conversation, breaks, and not having to worry about story lines...
however!!!!,,, by the far the best film to watch whilst tripping, dropping, rollin even stoned is crouching tiger, hidden dragon - trust me, its mental