I have this problem consistently at one particular hotel, and yet I never have difficulty elsewhere. I'm not sure whether it's a question of incompetent staff or outdated keycard technology. A while back, I remember Nikko Hotels would let you use your frequent guest card as a key. I don't know what happened with that, but it's certainly not something that caught on anywhere else. The airlines seemed ready to use the magnetic stripes on the frequent flyer cards in lieu of paper boarding passes, but then Homeland Security was born and innovation died.