Hinokan Sex Museum
There seem to be a fair few sex museums scattered around Japan. I can't say if the Beppu one is a good one or not, but it's there so I thought I'd add it to my list of things to do for those of you who're interested.
The museum is near the Kannawa hells, opposite the Hotel Ashiya. They have a large range of cultural exhibits from various cultures. Large wooden phalluses seem to be the most popular (especially the REALLY large ones). They say they also have life-size models that get stcuk into it at the push of the button - featuring Snow White and the 7 Dwarfs and Popeye & Olive Oil.... Snow White and the Seven Dwarfs doing it at the push of a button??? That's not kinky, it's just wrong! Anyway, if you'd like to experience the Japanese take on a sex museum Beppu might just be the place to do it.
Costs when we walked past were around 1500yen (ouch) and it was open from 9am to 11pm daily.