OK. You need photo-id to get your boarding pass. Since I always use
e-tickets, the boarding pass is the only "paper" involved.
Under normal circumstances for flights within the US the FAA seems not
to require ANY form of ID. It's many of the *airlines* that require ID,
supposedly in the name of security, but mainly to keep people from using
other people's tickets. Continental does not enforce an ID requirement
at SFO, for instance. You stick your credit or frequent flyer card in
the machine and it spits out your boarding pass, which you then hand to
the gate agent.