If you are shooting a static scene in low light, use the self timer or IR remote and something really solid, like the ground or a table. I took shots of cathedral ceilings using a 35mm P&S -- just hit the self timer, place it on the floor, and let it do its work. The smaller the camera and the wider the lens, the more places you'll find to stick the camera and let it take the shot. I've even placed a camera on an iron latch on an old door (and made sure nobody was on the other side, about to open the door).

A beanbag helps with fine positioning, but if that isn't available be creative - an eraser, a folded napkin, a wad of gum?