Tried jumpseating this last week. Here is my experience...

I am not in CASS due MLOA.

Tried Alaska Airlines: denied (even called gate agent supervisor/lead), but they stated if not in JACS (sp), Alaska's version of CASS, absolutely no way to jumpseat, not even in the cabin. Captain not allowed to overide like in years past.

Tried US Airways: same story, gate agents had no way of comprehending how anyone could jumpseat if not in CASS. No way, not even in the cabin.

Third time was the charm with SWA. No problem, checked all my documents - agents helpful - Got a seat in the back. Thanks much for the lift.