Rajars.

UK radio ratings came out yesterday...fun, fun, fun!
In London, Capital have a 5.6 share, followed by Magic at 5.5 and Heart at 4.7.
The ('all-important') morning shows has Capital followed by Heart and then Magic.
Radio 1 breakfast show went from 7.72 million listeners to 7.02 million(it's all relative, I guess).
Wogan's run on Radio 2 sees him go from 7.93 million to 7.76 million.

All the heavy numbers are here:
http://www.rajar.co.uk/listening/quarterly_listening.php

Paul Easton has a nice graphic of the London listenership here:
http://pauleaston.blogspot.com/2009/10/london-rajar-q32009.html