I'm still not convinced that "twittering" is a viable e-learning format. However, this article in ASTD Trends does have some good points - and some great resources for futher review. One good point:
"Think before you tweet. Each tweet is a webpage. It can be Googled. It’s forever."
Check it out: http://www.astd.org/TD/Archives/2009/March/0903_Trends.htm
Southwest Airlines Twitters: http://twitter.com/SouthwestAir