Stealth Cell Tower

Julian Oliver has disguised a GSM base station as an HP printer:

Stealth Cell Tower is an antagonistic GSM base station in the form of an innocuous office printer. It brings the covert design practice of disguising cellular infrastructure as other things - like trees and lamp-posts - indoors, while mimicking technology used by police and intelligence agencies to surveil mobile phone users...Masquerading as a regular cellular service provider, Stealth Cell Tower surreptitiously catches phones and sends them SMSs written to appear they are from someone that knows the recipient. It does this without needing to know any phone numbers.

(via Schneir's Blog)