As far as I am aware, we can't do reverse look-ups easily over here. If you ring directory enquiries and ask for an address given a number, they will not help you.

I think you can purchase tools such as those offered by 192.com that will allow you to do such reverse lookups. However, I don't think there are any online services that will allow you to do this (especially not for free) - I certainly haven't come across any.

I've also heard rumours that it's against our Data Protection Act for BT (the main telephone company in the UK) to give out addresses given a phone number. It's all rather confusing, some people say that you can't do reverse searches on private numbers but you can on company numbers.