The lancet do a series- neurology, oncology etc. They're really interesting. I know you can get them on itunes... I'll dig about for a link....
ETA: Here: http://www.thelancet.com/audio there's also infectious diseases and a standard lancet one. They're really good
Thanks for that. Having listend to a couple from thelancet, it seems they seem to focus on latest studies etc which although interesting doesnt really help a current medical student that much!