How do I store data for payment processing on a confirmation page?

The solution for this question is more specific to ASP.NET MVC, but the
solution that is needed is more of a standard across any web platform. I am
hoping maybe you guys have an idea.

I have all of the details of my question at
http://stackoverflow.com/q/7587953/2535.

Basically, I am working on an eCommerce application. After the person has
entered their billing address and credit card details, we want to display a
confirm your payment screen before processing the transaction. How do we
store that data so that we can continue with processing it after they
confirm the data is accurate?

One thought I have seen is storing the data (encrypted) in the session.
Another (that I don't like) is storing it in a temporary table (encrypted).
A third was to do a PreAuth and PostAuth with the card processor and just
deal with a (mostly) meaningless order id.

What have you done in the past? What is the "best practice" here?