Absolutely no chance of a jumpseat ride now.Prior to 9/11 you would probably been ok,I used to get jumpseat rides All the time when i worked as ground staff at our local airport mid 90's even if the cabin was half empty.
As the previous poster says only staff of the airline you work for will allow jumpseat rides, I think most airlines only allow it if your positioning crew and the cabin is full.
You may be able to have a look round the flight deck when you have landed,ask as you disembark although its not the same as being there for the flight.
Best wishes