Amusingly, in my collection of odd ID's and certifications (to include my radiotelegraph operators license in case I ever need to go work a radio on an ocean-going ship) is a TWIC card: Transportation Worker Identification Credential. Essentially, it's a SIDA badge for seaports and is issued by the TSA. Amusingly, a lot of times the TSA doc checker at the airport won't accept it. Oddly, the further away from the coast I get, the MORE likely they'll take it. One even told me that he doesn't see many of those. At CLT they didn't like it because they were testing this new driver's license scanning thing and they were trying to encourage that. At DCA the guy was a prick about not taking it so I filed a complaint with the TSA. I got a message from the national office saying that he should have taken it but they always have the right to demand a second ID. A few days later I actually got a phone call from the DCA TSA station chief saying that he was sorry, that shouldn't have happened, and the screener had been reeducated. Better response than I thought.
Of course the little piece of 3x5 card that has my FRZ pin that I got in 2002 is pretty worthless (don't even know where it is, I committed the PIN to memory).
I occasionally use my Passport Card. It’s almost totally illegible and the photo is so washed out it could be Osama Bin Lauden. Never been turned down.
Cheers