MikeL2 -- I spoke to a fellow this weekend who says when he gets a sales/suspicious call he exaggerates his (already broad) Yorkshire accent and ends up being hung up on. He figures that they give up trying to understand him because it's just too difficult if English is not your first language. Unfortunately, this won't really work for me (despite my best efforts to acquire a Sheffield accent!) ;-)

I am seriously considering trying a few words of French in such situations...