Christian H. at 2010-02-02 16:25:23:
I'd definitely agree that visual-visual transitions are the best way to show time.
I've used going down steps and coming back up; Econ 201 then Econ 301; newspapers are a great technique also.
I actually haven't found as many sound-sound transitions, but I'm working on it.
Oh yeah, a popular example is Dead Poet's Society - though it won't work as well in a tropical clime - where they use the passage of seasons - maybe that's why I used calendars.