As vaguely pointless but nonetheless desirable knick-nacks go, the Hermés 8 Day Spiral Boule Clock has to rank pretty high up on the list. A 1kg ball of magnifying-effect optical crystal, white gold and a total of 231 parts, the Spiral Boule is wound by twisting the two halves, while a single button on the base switches it into time-setting mode.
Inside, the simple hands move around the spiral clock face - also made of white gold - or you can flip it over to watch the mechanics at work. Hermés say there's enough power for 200 hours of use in-between windings, and that the inspiration for the design was a classic clock at the company's museum in Paris.
Of course, a large part of the appeal of something like this is the exclusivity. It's apparently a one-off, and priced at an eye-watering $560,000. Despite it being roughly the size of a cricket ball, then, we'd recommend you not actually hit it with a bat.