I've finally taken the plunge and created a blog.
If you may be interested, you can find it at http://blog.timbunce.org/
I researched these comparative job trend graphs for my Keynote at the 2007 London Perl Workshop:
http://www.indeed.com/jobtrends?q=%22perl%22%2C%22python%22%2C+%22ruby%22&l=