QUOTE(No one of consequence @ Wed 12th August 2009, 9:13pm)
Multiple hits in LexisNexis in the US, Canada and Australia. In the US, appears to be a novelty sport held at Scottish, Celtic or Highland Games-type of festivals/fairs.
Sticking a ferret down y'trousers is a well known Yorkshire activity, and the ferret legger is popular stereotype of a Yorkshireman.
According to WP, the champion ferret legger performed his feat in Holmfirth in Yorkshire, which sounds credible as Holmfirth is classic ferret-in-trousers territory. There's a whole episode of the TV show
Last of the Summer Wine (set in Holmfirth) about a guy keeping ferrets in his trousers
on YouTube.
I never understood why English culture and pastimes get transmogrified into Celtic blarney when they travel to North America. I guess the image of half crazed drunken ferret leggers doesn't fit the stereotype of the plum-voiced upper-class English gent, and so they get morphed onto the Irish or Scots instead?