Back in March Ben Hardwidge gave an excellent talk on shark conversation at Portsmouth Skeptics in the Pub. The audio is now available:
http://www.skepticule.co.uk/2012/04/skeprec-010-20120308.html
The "Sharks Don't Get Cancer" Myth
(For copyright reasons the videos — or rather the audio thereof — is not included in the recording, so if you get the chance to see Ben give this talk at your local SitP I'd recommend it.)