Slow boat from Cuba
Finally! Brian, in California, reports that my postcard to him mailed from Cuba has arrived!!!
I had actually given up all hope, given that most people I asked reported that postcards from Cuba to North America and even Europe usually arrived by a month after posting. (Granted, many of them would've been posting from Varadero or Habana, and we were in very rural Las Tunas.) I guesstimate, assisted by Google Earth, that the postcard took approximately 2.5 months to travel about 8850 km, or 5500 miles. That's one of the shorter trips the cards I sent will (or won't) take, believe it or not, so it makes sense it'd be one of the first to arrive.
Even if this is the only one that arrives, my faith in the Cuban postal system - and the US postal system - will have been bolstered.