Pins? I think those are actual cattle ear-tags.

I now want to book a vacation to the Netherlands to see the Graphic Design Museum...

I'm positive that neither MoMA nor SFMoMA has anything other than the paper ticket for admission.

I think MoMA used to have one, though -- would you like me to dig one out from my collection?

The MOCA in Downtown LA uses stickers. LACMA has tickets with photos of random, but famous, artwork printed on them.

The Franklin Institute (now not known as The Franklin), here in Philly, used to have these pins, I haven't been back in a few years, those would be worth recording in the history books.

We used to use kiss-cut stickers at MASS MoCA that were part of the actual ticket that the printer spit out with each paid admission. We made sure the date was prominently displayed under the logo on the right to try and stop people returning for free, which we found simple color-coded tabbed admission lapel pins could not prevent. Unfortunately, we found that people began sticking the patches on light posts in the parking lot upon leaving the museum. If you were so inclined, you could go in the afternoon and find a sticker there from the morning and get in for free. Obviously, as the ticket designer, I blamed the architects. The light posts are defective...

well, from what yall are saying, the solution isn't just the ticket, or the entry method, but the exit method. don't let the folks leave with a ticket! if they want, they can go to the gift shop for something memorable to hold on to.

Although I am not positive if they are still doing it, the Holocaust Museum in DC gives all of it's entrants cards with the identity and story of a Holocaust victim.