Looking for something different to do with DS (just had his 16th Birthday) we found Go Ape Segway. It was a real success. We have done the rope things before in France, but riding through the Forest on a Segway put a real smile on his face. The instructor was brilliant too. There was a younger boy who was really nervous, but was soon flying off down the tracks.
Ok, it's not the cheapest thing at £25 for an hour, but compared to something like Go-Karting it is great value, and great for a speacial treat as it is something so totally different to anything else.