I've got a friend who claims he's got a few satellite wifi rigs in his attic, and he uses netstumbler to point them around his area. Says he got 4 of them running, all on open WAPs, and teamed the connections together with a linux box. Claims he gets 40-50mbit overall with it, but there is a slight bit (20-40ms) of added latency.
I'd be interested in setting something like that up myself, though.