Tim-
Like the brake system, a hydraulic clutch system doesn't fail for no reason, so just trying to bleed it seems premature until a diagnosis is made. Is the clutch fluid reservoir still full? Does your car use a slave cylinder or a hydraulic T.O. bearing? I expect that it uses a slave cylinder system, with the primary cylinder being in the pedal box. Have there been any puddles under the car? If a seal on the primary or slave cylinder has failed, or if a hydraulic line has leaked, it should be obvious. Could the linkage from the pedal to the primary cylinder have broken or become disconnected? The clutch system can't just "acquire" air for no reason unless you've been driving inverted for a prolonged period of time, such as on the roof of a tunnel.
Just my $.02.