How many iMechanica users are on Twitter?  And how many are on Twitter with professional contacts? 

 I started to use Twitter about 4 months ago in a completely social, non-professional context.  As a personal (expat-focussed) blogger, I started to notice that I was
catching blog posts in my Twitter feed before I would see them in my
feed aggregator (Bloglines).   Twitter has emerged as a different sort
of feed aggregator, as well as a provider of information.