I’d have loved a Gomboc (may require registration, see here and here for other links) for Christmas – it’s a uniformly dense piece of thingee (i.e. it’s not weighted) that automatically rights itself if you tip it over (click here and wait for the animation to load to see it in action) – but I understand it’s really expensive. Apparently, each Gomboc comes with a unique serial number. One with serial number 12 would cost over 12,000 EUR, and one with 2007 would cost 1,000 EUR. See what I mean here – enter a number.