Sophie Calle

I looked at Sophie Calle, this was indeed the coolest, and most relevant (TACTIC), project:

"Auster later challenged Calle to create and maintain a public amenity in New York. The artist's response was to augment a telephone booth (on the corner of Greenwich and Harrison streets in Manhattan) with a note pad, a bottle of water, a pack of cigarettes, flowers, cash, and sundry other items. Every day, Calle cleaned the booth and restocked the items, until the telephone company removed and discarded them. This project is documented in The Gotham Handbook (1998)"