We are Teachers is a wonderful social network for educators that I'm just now starting to find out about due to the magic of collaboration. Luckily, I came across this in reading the comments online from one of my top 10 lists that was on T & L's site.
This is a network that is filled w/ innovative ideas on a number of different subject. Also, this community is filled w/ different educators from around the world so an array of ideas can be found here. Plus, people can receive prizes & cash by submitting their ideas and lessons.
I highly recommend checking out We are Teachers by clicking here, as it is one of the better online communities to come around in a while.