As this thread might attract lovers of radio comedy, I'll post a few links that I've offered here before:
1. ROK Radio has 17 channels online, two of which are dedicated exclusively to classic British radio comedy programmes (such as The Navy Lark, The News Quiz, I'm Sorry I Haven't a Clue, Round the Horne, The Clitheroe Kid, The Men From The Ministry, etc). Their Old Time Gold channel also carries similar material for a total of 6 hours each day:
http://rokradio.com/
(Note: The timings in their schedules should be regarded as approximate, with some programmes starting a little earlier or later than shown. It should also be remembered that the times are in GMT, so you need to add an hour during BST).
2. Abacus Radio has 9 streams, with one dedicated to classic British radio comedy. It carries the same sort of content as ROK's channels but there's no published schedule. They've also got a stream dedicated solely to Goon Shows.
3. GoonShowRadio is another source of 24-hour Goonery:
http://goons.fabcat.org/
4. Radio Echoes is a repository of old radio programmes. Many are American but there's quite a bit of British content too. For example, there are 247 episodes of The Navy Lark and 153 episodes of The Men From The Ministry. Programmes can either be streamed from the site or downloaded as MP3 files to play later:
http://www.radioechoes.com/
5. The Old Time Radio Researchers' Group has an online library of over 2000 series of programmes available for free download (rather than for streaming). The vast majority are American but there's some British content in there too:
http://www.otrrlibrary.org/c.html