This one is for the folks in Poland who enjoy the occasional pointless surprise. All you need is one of those ubiquitous black building intercom keypads and maybe a good memory for numbers, if you’re up to the challenge. Enter the digits 058758575130 in sequence and you will hear a familiar melody (possibly to the delight of a passerby who will surely think that you must be a fascinating person). And don’t worry about accidentally ringing, say, apartment 058—just use the key below the digit 9 to disconnect when you are done.
Where did I get this? A few years ago I was that impressed passerby when a guy was showing off for his date in Warsaw’s Różana. Neither of them minded when I swooped in for my little interview, and I’ve been entertaining friends and strangers with this one ever since.