This is classic, obviously the Google London headquarters was not consulted on this one.
As more publishers are being asked to complete the phone verification process, we’ve received a number of puzzled emails from our international community asking about the prompt to ‘press the pound key’. To clarify, the ‘pound key’ refers to the ‘#’ symbol (also known as the hash key), and not the ‘£’ symbol. The pound/hash key can typically be found below the ‘9′ key.
We’re working on perfecting our non-US English, and we apologise for any confusion caused
From here: http://adsense.blogspot.com/2008/02/in-for-penny-in-for-pound-key.html
This also falls under the category of the ultimate support call: “I can’t find the ‘any’ key.”