thing you get when you sit typing on the sofa for too long with
Ej Butik) in Latvia. They are orderable from Britain – they're around £30 each (and can be hand made to order, as they come in many different colourways and you can even supply your own fabric) but the postage is pretty chunky, at around £10 a pop.
But perhaps there are people elsewhere making equally ingenious devices, or perhaps seeing these will inspire you to craft your own. Do share some pictures if so...