- Tweetscan - Scan public tweets. Great for seeing what people are saying about your brand, product or service.
- Summize - Scan public tweets. Another service that allows you to see what people are saying about your brand, product or service. Also has a few more bells and whistles.
- Twittearth - This is a very cool tool that provides a 3 dimensional view of the earth and shows tweets geographically in real time as they are written. I like the little Twitter representations of people as well.
- Twitter Blocks - Shows the people you are following and who they are following and who is following you. Very cool graphical view.
- Twitter Fan Wiki - But if you really want to explore, go to this Wiki and check out all the Mashups.
Here is a fun and informative video on what Twitter is - "Twitter in Plain English"