Thanks both, it's usually another gadget that is cluttering the house within a few months.
Incidentally, on Mel's original link there's an interesting comment:
"Here’s the problem. The £300 limit has to cover all the small things that HMRC would regard as a “benefit” as it is there as, essentially, a de minimis reporting requirement. Exploit it in this way and you are exposing yourself to a tax charge on every other tiny “benefit” and, moreover, a penalty for not reporting them. The odd drink after work with staff or celebratory meal? Charging your mobile phone (or even electric car) at work? Even pinching the office stationery for your kids, for goodness’ sake! All of these things and more may be regarded by HMRC as taxable benefits and are tax-free only because the aggregate amount of them is “trivial” (ie. less than £300 in a year). So you need to take great care in exploiting this “loophole” lest you tip the overall figure (including the benefits you probably have not even realised are benefits) over the £300 limit.
I doubt it's enforced but it makes sense to use at least part of the £300 as a buffer rather than a target...