Do any other stores allow you to add gift certificates to an order after you have placed the order?

I place a lot of pre-orders with Amazon because they let me add gift certificates to an order after it is placed. Then I just add the gift certificates to it (I have a lot of referrals for some of these click for GC sites).

Anyway, I was wondering if there was any other company that did this...

Thanks in advance for your help...

As far as I know, you can alter the order up until it is phyically shipped.

I understand you can do that with Amazon, but I was wondering if anyone had any experience with other companies that will allow you to do the same. I suppose I should have put a ? in the subject - sorry for the confusion.