Ofcom has published some maps that it cooked up earlier this year, which predict 3G coverage from the five major mobile network operators - O2, Orange, T-Mobile, Vodafone and 3.
The maps were put together by estimating coverage from theoretical predictions, and show where customers have the possibility of making a 3G call outside. The regulator goes to great pains to say that they're not a guarantee of coverage, just a guide.
Still, it's interesting to compare the networks' coverage. It's no surprise that 3's is by far the best. Orange's is rather impressive too - nearly matching the newest entrant. O2's is very weak and no doubt causes some frustration for iPhone owners. Vodafone and T-Mobile's networks aren't particularly incredible either.
One thing that's interesting is how much of the coast surrounding the UK is covered. If you have difficulty getting 3G on your handset, then moving to a houseboat moored in the English Channel might be your best bet.
Update: Orange's VP IT&N, Pete Marsden, has commented: "Orange currently offers 3G coverage to over 93% of the UK population alongside more than 99% population coverage on our 2G network to provide the UK's largest integrated data network".
"We continue to spend more than £1 million per day on growing and developing our network to ensure our customers can make calls, email and browse the internet whenever and wherever they want".