www.payonebill.co.uk (I assume it's ok to post links!)
I currently use the UWDC for my line rental, gas and electric. You pay a £1.50 charge + VAT for membership each month, and providing you pay by Direct debit, you get one bill, and they *guarantee* that over any 12 month period you will have cheaper gas prices then British Gas, and cheaper electric prices then your regional supplier forever. Also they provide line rental at £9.99 (cheaper than BT), a great broadband deal if your exchange has been upgraded, and also if you take 2 services you get free weekend calls, 3 services free evening/weekend and 4+ services you get 24/7 free calls (all to 01/02 numbers) at no extra cost.
If your exchange has been upgraded and can take advantage of their Broadcall service, then they have a free laptop offer too at the moment.
It all comes on one bill and you pay one direct debit on the last working day of the month. The customer service is all in the UK, and you are hardly ever on hold, and i've had no problems with them so far, and compared with what i've paid British Gas & EDF in the South west over the past I have certainly saved some money, so it might be worth a look if anyone is interested!
