On our old system we had "e-gift certificates". You could purchase them for any amount...say 102 dollars. Upon purchase the gift certificate would be email to you (or as a gift to another). The gift certificate could then be printed out from the email. It had a customizable template an id that could be cross-checked against against the internal orders. So the front desk would know that order #12323
was REALLY for 102 dollars and not 50 dollars.
Does a similar functionality exist with Foxycart?