Last week I had the opportunity to flog the game I am working on at the GDC (specifically at the GDC Play Pavilion), where the Museum of Art and Digital Entertainment were also hosting a History Of 3D Games exhibit. They were showing off a handful of influential 3d games from the last few decades, Among which was a Pippin, running a copy of Super Marathon:
http://www.moonbase-industries.com/stuff/IMG_0221.JPG
(sorry for the bad quality, indoor iphone shot)
It was pretty neat! The controls took some getting used to but it was very playable. I never thought I would be able to see one of these things up close, let alone play it.
They also had a still-in-shrinkwrap boxed copy of Marathon on display (which I didn't get a picture of, but I am pretty sure they got off the same person who is/was selling a bunch of these on ebay, mentioned a few weeks ago here.) Cool stuff!