In this book, the first time they explain what a port-key is to Harry, they tell him it's an object that is preset to a specific time and if you touch the object at that time, you will be sent to another place with it. Correct? I thought so. But in the end of the book, Harry and Cedric touch the Cup (a supposed port-key) and are immediately transported to the middle of nowhere. That last task wasn't timed, and in fact they both took a while to get there and even hesitated in taking the cup to each convince the other to take it....so how could they have been taken somewhere else if the Cup had been timed, which it obviously would have been, since it was a port-key, unless Crouch Jr. knew exactly at what time they would get to the cup? This, is of course, impossible, unless he has some weird kind of divining power J.K.R. didn't mention.