VoIP User gives you a free number in the UK and lets you terminate calls just about anywhere. If you have friends in the UK sign up for one of their numbers that lets you point it to a phone in your country to a PSTN number.
Here's a great use for this is for those that travel and have CallVantage. Get a UK number, have it call your CallVantage Message Center, check voice mail, return calls, and make outbound calls from the UK as if you were in the USA, all for free...