If you're interested, please check out my blog about my friend and I having a day of complete misadventures and being totally duped by scammers for selling punting rides on the river around the Cambridge University campus! Photos of the day included.
Thanks!
Also if anyone else had a similar experience to us in Cambridge, I'd love to hear about it because it was just so unexpected for us!
Unfortunately Britain does have people who set out to dupe tourists.
In London, I frequently go past a man (the precise personage sometimes varies), often to be found near Leicester Sq tube station, calling out something like "Anyone lost, needing help, advice, directions..." and carrying a number of folders. You'd have to be pretty gullible to approach such a person, but doubtless having carefully selected only the pretty gullible as his marks, he makes a living from them.
This particular case is rather sad, because when I was at Oxford there were students who informally marketed "have a tour with a real student" tours and the like: and they were often personable well-dressed and well-informed types who gave tourists an entertaining time for a reward modest in comparison to what a professional guide would charge. Indeed some also did it for no personal gain but as fund-raising for charities and other causes.