sounds like the same symptoms I had when my slave cyl went. I gave it a hard shift to 2nd and the pedal basically stayed on the floor - took a few minutes to come back up. $28 later and a new one is fitted and all is sweet and dandy.
edit: if you get a mate to look under your car as you sit in the car and STOMP the clutch pedal, he will probably see some leakage from the slave cyl if that's what has gone. if not, check for leakage around your master.