Multimedia Links

First, there are many good multimedia resources available online at
http://encarta.msn.com/mediacenter_/browse.html
There are all sorts of resources (videos, interactive media, photos, sounds, charts, etc.)
and they are sorted by subject area, whether you teach Grade 12 Chemistry or Grade 2
Social Studies.

I have found Powerpoint templates (in game show format) by Mark E. Damon to be some of the best. 
Some of his downloads are available here.
http://jc-schools.net/tutorials/PPT-games/