Yeah, there's this new-fangled invention called a photograph. That's the new trend in mementos.

Seriously, I don't think a couple of locks of hair would be that creepy by themselves. It is a bit archaic, but it was common practice for a long time. The thing that makes it creepy is the collection aspect, rather than a heartfelt memento. And the condom ring thing is just gross and creepy by itself.

And people do keep mementos other than photographs, of course, but it's usually stuff that is personal to the individual, again not some creepy collection like you're a serial killer keeping trophies. Cute notes, souvenirs from trips, dried flowers from a bouquet, small trinkets given as gifts--that's what most people keep.