No they're not.
I think the BBC are missing out on a great opportunity to cash in by not making them available.
I've found them all to be very good. Radio being an excellent medium for Fantasy.
I've downloaded a program called "Radio Downloader" that can be programmed to save such items. Once you mark a particular show you are interested in, it will automatically save them for you.
As well as several adaptations of Discworld books, there was also a very good one of Nation.
Look, you've got it all wrong! You don't NEED to follow ME, You don't NEED to follow ANYBODY! You've got to think for your selves! You're ALL individuals!
Yes! We're all individuals!