The BBC is currently broadcasting a radio adaption of Pratchett’s Guards! Guards!, on Saturdays at 6pm. Episode 1 (of 6) was broadcast last Saturday and is currently available on the BBC’s listen again service.
If you want to access this you will have to go to the BBC web page http://www.bbc.co.uk/. For non-UK people when the page comes up click on “UK version” at the top of the page. Then scroll down to the radio section. Click on “Listen to shows you’ve missed.” A new window will open up. On the right under the head “SPEECH:” click on “Arts and Drama”. Scroll down to “Guards! Guards!” and click on it. The show require Real Player to be installed to listen to them (it will download and install if you don’t have it) or an alternative (I use Media Player Classic).
Episode 1 will be available to listen to until Saturday and then will be replaced by Episode 2.
It is possible to actually download the recording, I use Streambox. If you require help with this, email me.