It would make sense for it to have been in my laptop bag, which collects lots of electronics at some point or another. Perhaps in one of the winter jacket pockets. Maybe even my blazer pocket, since the last time I'm sure I had the thing was Thanksgiving weekend in NYC and Newark. Dining room table? Nah, cleared several times since. Dining room side table? Unlikely, but no. Basement? Boy, I hope not. Under the bed? In one of the pieces of luggage?
Finally, this morning, after another round of searching, it occurred to me to wonder where I would put the thing if I got the urge to "put it away." Where would I decide it belonged? Unlikely a concept as that seemed, I decided I'd probably put it in my top dresser drawer. Sure enough, there it was -- right next to my passport. (That's one of those things I know I need to be able to find reliably.) I'd looked in there for something else about a week ago, but since that's not what I was looking for, it didn't leap out at me.