Easy-to-take-down portable Projector setup?

[AmusedToDeath]

The house I live in does not have a room suitable for a permanent home theater setup. I already have a 55" tv and a 5.1 receiver wired up with wall jacks and all that in our living room, but that's the room you walk into through the front door - there's no way we could keep a screen and stuff up in there. But it would be nice to occasionally have a theater-like experience with a projector and screen every once in a while with the kids.

The projector and screen seem like they would be easy enough to set up and tear down once a week or so, but the issue of decent audio seems trickier. If I'm going to have to run cable and move speakers around every time we want to do this it's probably not going to get used much and destroys the all-important WAF.

Has anyone else done a "temporary" home theater setup like this with a projector and screen? If so, how have you overcome the aforementioned issues? Thanks for the help.