Tourette's syndrome.
With the airing of last night's "Tourettes: I swear i can't help it" on the BBC I thought i'd post it hear both to highlight the condition to those of you who haven't heard about it...But mostly to give everyone a good fecking laugh.
The bits with John and Chopper with the people from Citizen's advice is brilliant.
http://www.bbc.co.uk/iplayer/episode/b00ksj56/Tourettes_I_Swear_I_Cant_Help_It/
watch from 19 minutes on for the best bit.
John is also the star of 3 other Documentaries about his life with tourettes
John's not mad....the follow up to John's not mad...and Tourette de France.