I’m in the process of putting together a presentation about some of the best FREE Web 2.0 sites for educators. Nothing too heavy, this is going to be a whirlwind tour of free tools available to teachers that they may want to take advantage of. What do you think are three sites that absolutely MUST be included??

Here’s the guidelines:
1) I’m only looking for free sites. If the site has a free as well as paid service (like Flickr), only suggest it if you think the free features make it worthy. Timed free trials don’t count and shouldn’t be included.
2) Only suggest sites that you think would be worthwhile for educators to make use of.
3) I’m using a very loose definition of Web 2.0. So loose that I won’t define it here ūüôā

Vote using the form below. I’ll publish the results in a future blog post. And if you want to do some more typing, feel free to vote for your favorite 3 in the comments and let everyone know why you chose them.

UPDATE In response to an email I got, I’m actually using one of my favorite web 2.0 apps to handle the form: DabbleDB. However, since there’s no free version (they have a 1 month free trial), it won’t make this list.