Did you know @Alan that a good alternative to a Sim Card adaptor is to get a cheep prepaid SIM Card with the various punch out sizes already cut and just use the size you need? In Australia (as we'd expect most of the world) cellular/mobile carriers and phone shops will have a few of these and some used ones too, they may if you ask nicely give the adaptor to you for free.
Happy to Help,
Marcus 
