You can still listen to BBC iPlayer Radio via your browser by visiting bbc.co.uk/radio
Philip Pullman reads the third of his Grimm Tales, and Mel gets to the bottom of nanotechnology which, among other things, makes your mobile phone work.
See all episodes from The 4 O'Clock Show
See all clips from 11/12/2013
See all from 11/12/2013
See all broadcasts of 11/12/2013 (1)
Sign in to the BBC, or Register