I've found the two person shower.
No, it does not have two shower heads, but instead takes two people to use. One person gets to take the shower, the other person has to operate the controls since the shower goes from hot to cold every 10 seconds. Even with an operator, the person taking the shower gets scalded and/or frozen every few seconds.
Excellent plumbing job!
BTW we are working on a 5.0 release candidate for MySQL. Sure, this has nothing to do with showers, hot or cold, but it will make Zack happy that I added this to a blog entry since the LJ "post multiplier" sank the planetmysql site and of course nothing was mentioned …