Short term accounts for group purchases - but for a lot of groups

Zuzzy

I am thinking of setting something up, one part of which would allow people to pay their part of the overall cost for a larger bill (eg a group booking for a stag do) into an account when they are ready and once everyone has paid the lead can then spend that amount on whatever they were saving for.

I'm not worried about the 'having to trust one person' part of it, what I want is a service like paypal but with no commission (given they get the interest, this seems a reasonable expectation) such that I could set thousands of them up easily and basically provide an interface into the system.

I have seen things like investment clubs, crowdfunding and obviously paypal, but none of them quite do what I want. And it would be even better if you got given a visa debit number so you could spend the amount anywhere online. I did think of the PAYG mastercard cards but I havent found anything set up for the numbers I would want to use.

Any ideas?