There have been multiple real life events where players meet with ARG actors or game devs, and receive objects from them that are important to the ARG.

These events are:

Berkeley time travel abduction event (2014-4-5) yielding frog statue and bug porn floppy disks

Indiecade (2015-11-26) yielding Luigi Amiibo

The Quartz (2016-01-20) yielding a bag of quartz.

Museum of Jurassic Technology chess event (2016-2-18) yielding Mario Amiibo

Game Developers Conference (GDC) (2016-3-20) yielding a business card