f4f3 | Prague Question

I'm off to Prague tomorrow to do best man stuff. In all the excitement, (punk) I haven't got any Crowns yet - I can't remember now how easy it is to get Crowns abroad. I seem to remember changing money at the airport last time, but I haven't been there for a while. Does anyone know if Pragues the sort of place it's just easier to use your cash card from home?