I haven't promoted buy.at but I'm a member and they have loads of big brand UK offers. B&Q, ASDA, AutoTrader and all the biggest betting, insurance and mobile companies.
^^ yeah, it was pretty cool getting transfers from them when GBP was more than $2 CAN and lameass CapitalOne was accepting 90% of loan leads 3 years ago
Direct Agents allow you to sign up different accounts in diff currencies. They're a US (or CAN?) network, with a UK branch. I have 3 accounts with them - in US dollars, euros and pounds.
Market Health is a health and beauty network with heaps of offers for the UK and Europe.