An idea bubbles up through the building

The thing that interests me most about the Guinness visitors centre in Dublin is the notion of a physical token that both enables the visit and serves as a reminder of it. For the Guinness centre, the token is a plastic 'pebble' that contains a little drop of the black magic itself. Apply that to a corporate work environment: instead of the standard visitors' badge, what physical token might serve - for example - as both a temporary pass and as a tiny memory of the visit? Is there some value in that? One for the brand people to ponder.