Here's another trick we used. We had fastpasses for Test Track but couldn't use them as it was broken down. The CM at the entrance gave us tickets for the next day, but we weren't there the next day. We were also able to keep our original unusable FP's. We noticed the CM on the entrance changed as we left, so we went back and he gave us another 4 tickets for the next day.
As it happened, it was three days before we went back to Epcot, but I had realised that it was unlikely that the CM's would look at the dates, they only look at the times. I was right and we rode Test Track three times each in one hour with FP's that were two or three days out of date.
I did consider bringing some unused FP's home and seeing if I could duplicate them on my colour copier, but I forgot! Anyway, that would be cheating and we English never do that!
