I love radio and have done a little bit for years - since 'Workers' Playtime' in the 1950s. It's also a good springboard for comedians.
In the old days, if you topped the bill one evening, you'd do 22 minutes maximum, and if you overstepped and did 27 one night, you'd get a knock on the door telling you it wasn't acceptable.
What is so good about 'Gavin and Stacey' is that it is very real, Welsh, and well written.