>Let's say, hypothetically, I want to wirelessly network my house to a
friend's
>house.

>Project parameters:
>- Least expense as possible (isn't that always the desire?).
>- Center of my lot and his lot is about exactly 330 feet (100 meters = 328
>feet), at the edge of wireless range.
>- It would be "fixed" wireless on his end to his desktop PC.

I'd recommend going Ad-hoc using cards that support external antennas.
Buy cards that allow external antennas (like Lucent/Orinico). Use a PCI
adapter for his end.
Build/Buy 2 Cantenna's
Buy pigtails to connect it up

Estimated cost under $200.