Evgeny Morozov delivers a good analysis, as usual, of the Twitter hype. Beware:

Twitter use in authoritarian countries comes with major drawbacks. Twitter creates an extensive online paper trail that can be easily used against dissidents. In fact, as Twitter use becomes more common, authoritarian governments are likely to exploit Twitter to gather open-source intelligence on the opposition — not a difficult task for anyone with an Internet hook-up. So Twitter could help authorities identify dissent at very early stages, tracking not just individual activists, but entire activist networks. An online friend list could enable a serious crack-down.