I haven't tried constructing one yet, and I'm sure some people here have seen this, but in case some of the newer people haven't....check this out.

Primestar Wireless Antenna

now I just gotta find one of those satellite dishes. I have an extra DirecTV dish, but it isn't as big, so I would imagine the gain wouldn't be as high.

*runs and gets tools*

enjoy.

t.e.k.n.o