Because we decorated houses last year, I already knew what presented the largest obstacle to this activity-- the construction of the houses-- so I got an early jump on that by gluing them together in advance. This is best done with a hot-glue gun, but if you forgot yours upstate (curses!) you can also resort to gluing your gingerbread pieces onto a cardboard box with some wood glue and a little blue painter's tape. (Unconventional, I know, but it totally worked!) I assure you, this is a much better system than trying to assemble the gingerbread house using only the frosting provided after everybody's already had a couple of drinks. We tried that route last year, and it ended in some very misshapen roof-lines. : )
We built two houses, which were equally successful, in large part because the majority of our dinner guests were once art school attendees. I briefly considered building four houses and holding a couples decorating competition, but then I realized I'd end up stuck with 4 gingerbread houses, and that seemed really unappealing.