Does anyone know whether a visa is required for a U.S. citizen? The U.S. State Department says, quite helpfully, that "all travelers to Yemen can also potentially obtain entry visas at ports of entry." It seems from the remainder of the paragraph that with the usual documentation they will issue it on arrival.

But it would be nice for someone with first-hand experience to report.

(I have been planning a trip to Djibouti, possibly on the same itinerary as Yemen, and found out as definitively as it's probably possible to that one can get a visa on arrival at JIB. The Kempinski hotel told me this; it turns out that they have a whole lounge of their own at the airport to facilitate things. Sounds like fun! Hopefully early next year I can do both countries.)