Yup, a bromeliad of some sort as Michael F suggested. It's pretty hard though to ID it when it's not flowering, as there are many many varieties of them.
wow! i've never seen a bromeliad with purple leaves!! it's beautiful!! lila is probably correct with the guzmania id...
It appears we have an answer - I did some googling on Guzmania lingulata and my plant looks very very similar. Thanks everyone for your help!