The DEN Virtual Conference (where I am participating in-person) continues with Jen Dorman's session on learning networks. Of course, the Discovery Educator Network leads the pack, but she also made us aware of a network created by PBS and Google. Twitter and Plurk still prove to be the best, but Twiffid filters only web addresses that are posted on Twitter. You can also follow plodt on Twitter and it graphs Twitter posts to give you an idea of the conversations happening so you can join. Phweet turns Twitter into an instant message chat. This might work if Twitter is blocked in you district.
Diigo and Delicious are similar, but Diigo allows you to create groups and share annotations/bookmarks with others. Diigo will also automatically post to blogs.
I had to tune out because there are dozens and dozens of other resources Jen is sharing, so I am going to focus on posting to Diigo and Delicious, signing my students up for accounts in Wikispaces for collaborative purposes and beginning my blog on the DEN web site...and cross-posting here and on blog.mtlsd.org/cybrary.
Oh, Drop.io looks pretty cool too. I'll check that out also. Jen rocks!