I have a requirement to be able to accept different forms of payment within the same order - ie not just the usual credit card or paypal for the whole thing, but perhaps paypal for one item, cheque for another. I know this sounds quite crazy, but there is a good business reason for the requirement so I can't just push back.

The best way I can think of implementing it at the moment is to have kind of a hub page, where you can "launch off" into multiple flows for each of the payments by opening new windows. I can't figure out a way of doing this in a linear flow as for example you can't guarantee that a user will come back from paypal, so you'd then lose the user completely.

Is there a neater way of doing this that anyone can think of, or can anyone point me to an example of a site that does somethign similar for inspiration?