I used a credit card. I use it exclusively for things I do online/phone so that I can just cancel it if there's anything 'unpleasant' happens without it affecting my debit card/account.

Mind, I have rather good credit, and pay off every month. Last month's bill was over £700 including £590 university fees, so they wouldn't see an expenditure like this as unusual.

What I find more encouraging is that having waited, they are now taking people's money. That suggests they are finally serious about sending our n900s!!!!