I just came across a new feature in iGoogle that allows you to share tabs with others. This has the potential to be very useful if a school implemented iGoogle as a student start page or "virtual planner." Instead of trusting students to put useful gadgets on their start pages, you can give them each a uniform template which they can then customize.
I posted a screencast of how to create the template on my blog. If you're not familiar with iGoogle, I would recommend that you watch the video below. You might find something useful for yourself or your students!