I was in Wolverhampton today where I passed a shop selling discounted ex-catalogue electrical goods. Under the name of the shop, in large bold letters were the words

The shop that defie's the credit crunch.


I am constantly amazed that there seem to be people out there who believe that every word that ends with "s" must have an apostrophe.

I agree. I can see getting mixed up as to whether it's an adjective or possessive, or maybe getting "its" and "it's" confused, but there should be no confusion in that situation.