Checking out my feed and I can see I´m already 4 days behind, no good... Moist towelettes are an interesting thing to collect and with 300 pieces, you must have been one of the world´s most successful collectors of this item. My wife collects (hoards might actually be a better term) various weird things, airplane vomit bags (unused :D) being one of them :)

Interesting question for this HPUD guessing contest. My long shot would be Warsaw, Vilnius and Riga :)