Here's a pretty pretty watch: The new Botta Uno 24, a german time machine that has a 24 hour dial and one single hand, which rotates at half the speed of a normal hour hand. Made of stainless steel and capable of resisting three atmospheres of pressure, the manufacturer says that each of the marks in their watch corresponds to the actual position of the Sun in the sky. Whatever. We just think they look like a nice present for $395.
I love this.
As a usability professional, it's not often that I get to point to something so common as an example of bad user experience, but the artificial AM/PM distinction is definitely a key offender. I understand that it's hard to cram 24 hours onto a readable dial (this watch doesn't look too bad), but we should really be making more widespread use of 24-hour time, especially now that so many clocks are digital.
Try it for yourself on your own clocks... you'll never set your alarm for the "wrong" 6:30 again.