Last year we flew to London for a few days and then took the high-speed train through the Chunnel to Paris. While in London I bought a dandy Victorinox Swiss Army pocketknife with lots of blade/tool options, including a corkscrew (which got LOTS of use). Rather than give it away when we departed from Amsterdam for the return flight, I shipped it home to myself for about $7US, which was cheap considering I paid about $50US when I bought the knife in London.
This fall we are flying into London again and taking trains to Bath and Edinburgh before flying over to Copenhagen for more stops on the Continent. According to what I found online, passengers can take small pocketknives in their carry-on luggage if the blades are no longer than a certain length (which I don't have in front of me right now). When I checked and did a conversion to inches, the length amounted to about 2.34 inches. If I shipped my knife to the hotel in Bath and tried to get it on board our flight, how picky are they on the blade length? ... I think I'm just a smidge over the prohibited length.