Useful Web Apps...

Prezi - Best presentation tool EVER.

Scribd or docstoc- youtube for documents

Microblog site - useful for real-time comments in class

Screencasting - for a change from Powerpoint

Empressr - yet another (easy and attractive) presentation package

WORDLE - word clouds. Very cool!

COLLABORATIVE MINDMAPPING - BUBBL.US...

... or mindomo (again, collaborative mindmapping)

DIIGO - Annotate the Internet

EYEJOT - send video messages. More fun than email...

myplick - upload, embed, share presentations. Or use slideshare (slower, buggier but better known...) to do the same!

SCREENTOASTER - Best screen recorder ever!