I use Wordle to generate the image, the ROME RSS reader to download the RSS feeds, and Java software from Inon to process the data.
You can also see the Java version in the Wordle gallery.
It is written by Leigh Caldwell (email me at email@example.com).
My other blog is Pricing Revolution, specifically around innovative pricing models and advice on how businesses can set their prices.
I am also founder of think tank Intellectual Business which publishes research and policy papers on how ideas from economics can be used in business and in the public sector.