Breathalyster Watch: Kisai 'Intoxicated' Watch By TokyoFlash Tells You When You're Drunk

Modern watches are increasingly multi-function - they can tell you how active you are, if you have any emails, and - well, actually we're not sure what this one says at all.

But a new invention by crazy Japanese watch makers TokyoFlash might just be the most unique watch yet.

The Kisai Intoxicated LCD watch includes a built-in breathalyser test which can tell you when you're drunk.

The watch, which costs just $99, isn't intended for drivers - if you've had enough alcohol to need to ask it if you're okay to drive, you probably aren't. But when you're enjoying after work drinks and about to spill the beans to Bob from Sales, we can see how this sort of thing might come in handy.

Check out some of our other favourite weird inventions, below.