Swisscom, sunrise and Orange all have shops at the airport which are opened daily from 8am to 9pm:
http://www.zurich-airport.com/deskto...id-816/csec-1/
Also there are a KKiosks which sell OK mobile SIM cards that offer some
interesting data options.
Except for Orange you will also find all these shops in the underground mall "RailCity" beneath Zürich main station:
SBB: ShopVille-RailCity Zürich: Shops.
With a swisscom "Natel Easy BeFree" SIM card you can immediately start using data at CHF 4.00/day (you won't be chared the call or text rate unless you place an outgoing phone call or send a text). For other SIM cards it will take a couple of minutes before your ordered data option has been activated (wait for a confirmation by text).