You've got a new billing option in Google Play if you're a customer of Canadian carrier Telus or O2 in the UK. Fire up the Play Store, and you'll see carrier billing pop up in the checkout screen. Yay, another way to give Google money.
Support on both carriers has been confirmed, but only O2 has said anything official. Carrier billing is useful for people who don't have a credit card, or simply don't want to give it to Google. The charges are added to your wireless bill and you pay them at the end of the cycle with everything else.
Google also added PayPal support to the Play Store a while back, but not everyone wants to use that either.
Update: Google has updated its support pages to include Etisalat in UAE and FET in Taiwan.