The multimedia discovery missions from NOAA Ocean Explorer provide students with an amazing resource to supplement the learning process. Here, students can watch video (FLASH) presentations or still pictures and text (HTML) of the same topic. Great for English Language Learners!
This website can be used to assist students in mastering the Geologic time scale. I would use this in my class by making up a scavenger hunt, and students would have to find the correct geologic time period for a certain organism.!