Don't you? Sure you do. See my wife thinks watches are sexy on men, and that I should get one.
Although I'm not sure this item would meet her criteria.
The first one out there was from Citizen, and would alert you if you abandoned your phone, as well as tell you you had a call visually when the phone in your pocket was on silent.
Yikes that is ugly.
For $400 you can get a Sony which lets you "know you have a phone call because your watch is vibrating and the display shows a new SMS has arrived. You're in touch but nobody has to notice."