Misadventures in Learning: What's a Twitter Chat?
Intro to Twitter chats like #lrnchat, including how it works and tools to make participation easier
BackTweets
Enter a URL & see Tweets with links to that site
BackupMy.Net Dashboard
Backups for email, blogs, photo accounts, and Twitter. To get a free Twitter backup, you need to Tweet about the service once.
Collecta
Collecta calls itself "real-time search." It focuses on searching blogs, Twitter, news sites, etc. rather than more static web content.
What is social media? A simple social media map « Donald H Taylor
5-minute slidecast on different types of social media, comparing content-focused and people-focused tools