Odwiedzam ten weekend i chciałbyś spędzić bitcoins a ja jestem tam.
*tłumacz Google*
So, there is a few places, where you can spend your bitcoins, but I'll describe places, which I've tested personally.
1. Bobby Burger (to find on coinmap.org, near Złote Tarasy shopping mall and Pałac Kultury i Nauki) - you'll find there one way bitcoin atm and also you'll be able to buy good burger and beer. I paid there with BTCs several times and it's not a problem to manage a bitcoin transaction.
2. Equilibrum Pub - it's not on coinmap.org right now, but it's located on aleja Niepodległości 147. It's not so user friendly as Bobby Burger. When I was there to test bitcoin transaction I got a feeling that I'm an some kind of alien for the stuff. Moreover I had a problem to pay tih BTC there, so for me much better place is Bobby Burger.