Have a look at Joe Dale's blog at http://joedale.typepad.com/

Joe is very active on Twitter and he manages a very informative blog. His latest posting, "Getting personal at Language World 2011" (27 August 2011), focuses on the benefits of using Twitter for CPD, especially - as he puts it - "In light of the current economic downturn and the difficulty teachers have of getting out of school to attend courses."