My friend Chris Helm, who is a co-conspirator both at FortiusOne and on the organizing committee of FOSS4G, has been doing a lot of interesting work with analyzing and mapping tweets recently. He produced a cool animated map showing the location of tweets tagged with #Egypt #Jan25 or #Tahrir over time.
View full map
When you play the animation (click through to the full map and press play at the bottom left) you can clearly see the moment when Mubarak finally stood down, everything goes crazy. Diane Sawyer from ABC news featured the map on her blog too, which was very cool!