For Future Reference...
When I showed up at Schiphol Airport on Friday afternoon, I was planning on taking Northwest Airlines to Memphis, since I knew that Northwest offers international jumpseat and that flight had plenty of open seats. My first inkling of trouble was when I approached the KLM ticket counter to request the jumpseat and the agent said "Jumpseat? We don't do that in Europe. Do you have a nonrev pass?" I politely told her that although KLM doesn't do jumpseat, Northwest does. She found a supervisor who did know about jumpseating; she informed me if I wished to jumpseat, I'd need to have my own NWA jumpseat forms, because KLM does not stock them. Ouch. I'll know better next time.
There were only a few flights to the US left that day, at least on jumpseatable U.S. carriers. I tried United; their ticket agents mistakingly claimed that they don't offer international jumpseat. I tried Delta; they were full. At this point I had a very heavy, sinking feeling in the pit of my stomach. I'm going to get stuck here, miss work, and spend a ton of money. I'm an idiot for not buying a non-rev pass! Fortunately, the next carrier that I tried, USAirways, had jumpseat-savvy ticket agents and some seats available on their flight to Philadelphia. I had just enough time to pay the departure tax (€41! Ack!), go through customs and security, and get on the plane. The only reason it worked was that I took an earlier train to the airport than I originally planned. Otherwise I would've been stuck for the day, and possibly all weekend.
So have I learned my lesson? Will I never attempt to jumpseat internationally again? Eh, I'm a bit too much of a cheapskate to pass up a free ride. But I'll definately bring extra jumpseat passes with me next time, and do research on backup flights beforehand even if I'm trying for one that seems foolproof.