Although guide books aparently dismiss its overtouristization, Yufuin is a more pleasant destination than we expected (although it is expensive, as advertised). It makes an ideal day-trip from Beppu (often compared to Las Vegas, but with hot springs), or a long afternoon stop over on the trip acros Kyushu.
Get the excellent English map from the tourist information, and rent a bike if you want (but it's not really necessary). Make sure to pack your onsen gear into your day-pack (towel, soap, etc.).
Head *away* from the tourist-trap thick street, and instead head out to the suburbs, towards the spot on the map marked clearly "Photo Gallery and Fried Chicken." No, this is not another mistake in translation, but instead you'll find, exactly as promised, some very greasy (read: tasty) fried chicken, and a small gallery of cheesy photography (including some tacky digital art). The fried chicken will run you 750Y or 1950Y for a set with rice and other sides, but towards the end of a long Japanese journey, you'll find that it's worth every penny.
You can then wander through the side streets, slowly making your way towards the lake at the foot of the big mountain. If the lighting is right, you'll have opportunities for some pretty pictures of the volcano reflecting in the rice paddies.
At the lake, enjoy some onsen, try the ice cream in the basement restaurant on the north side of the lake (1000Y for two) - they've got a huge picture window of the lake and the presentation is really quite lovely. If it's getting to be dusk, you might be lucky enough to see a show of jumping fish and swooping birds (with the associated mosquitos and whatnot). Everything here is just lovely.
If the day is young, you can head for a nice hike up the side of the mountain (which Hillary and I didn't get a chance to do). You might need to catch a bus to the base of the mountain (ask at Tourist information if you are interested).
The walk back to town is through the commercial tourism mire that Japan is full of, complete with the Marc Chagall and Norman Rockwell museums. (Along the way somewhere there is also a stained glass museum, too). A word of warning. Traveling here on June 1 was ideal, but it must be *miserable* when there tourist hordes arrive. Probably the earlier in the season the better. They come for the Yufuin hot springs, which I've given short attention to, but which are found everywhere in town - some cheap and basic, some expensive and exclusive. If you're in the mood, (and the crowds aren't too insane), definitely partake.
Morning in Beppu found us waking up in another lovely hotel, if you know what I mean. We finally got to experience payment by pneumatic tube, which is a singular experience. Just send your 10,000Y up and away and a few seconds later, that giant wooshing sound returns with your change. This spot was the best deal yet, with check-in at 8pm, check-out at 11am for only about 5,000Y (most places are 2,000Y more for 10-10 access). Today, off we are for more onsen soaking. This is the way honeymoons are supposed to be!