Oh, twitter, I love thee, how do I count the ways? In a burst of year end enthusiasm, programmers and analysts alike have done a push on state of the twittersphere data.
HubSpots's got a Technorati-inspired State of the Twittersphere PDF, and flip kromers got  interesting data extraction/spreadsheet/database material.

Some stats from Hubspot:

• Twitter is dominated by newer users - 70% of Twitter users joined in 2008
• An estimated 5-10 thousand new accounts are opened per day
• 35% of Twitter users have 10 or fewer followers
• 9% of Twitter users follow no one at all

Data from a  scrape of the twitter friend graph by Phil'flip' Kromer

• about 2.7M users
• 10M tweets
• 58M edges
• 219,000 #hashtags
  
• full metadata on users and relationships
• calculated pagerank for users

http://blog.hubspot.com/blog/tabid/6307/bid/4439/State-of-the-Twittersphere-Q4-2008-Report.aspx