If you're going to do that, you have to take the gnome with you and get photos of him in the various locations.My hubby's mate nicked a garden gnome from someone's front yard while on holiday in Esperance many many years ago- he thought it was funny to send postcards from all over the place and sign them from the garden gnome.
I'd be pissed off if it was my garden gnome- maybe I just don't have a very good sense of humour when it comes to stealing stuff. Fair enough - it's funny if you intend to return it one day.