Own a Nokia Lumia phone in Poland ? Your taxi ride is on Nokia
Inside the city of Warsaw, Nokia Lumia owners get free cab rides
If you follow all of the rules, all you need to do is show the cab driver your Nokia Lumia phone and the fare is covered by the Finnish handset manufacturer. It's too bad that Nokia doesn't expand this promotion to, say, New York City but that might end up costing Nokia a lot more than the promotion is worth.
source: Reddit via WMPoweruser