I havent checked to see if I can get the signal from the roof.
No laptop.

My neighbor is distributing his signal with blessings from the ISP, so thats not an issue.

Where and what kind of directional antennas are available?
Are they expensive?

I'm still kind of hazy on what I need to do with the coax from the antenna.
Say I get my hands on a crappy old laptop and I can get a signal from my roof with a directional antenna. I then pipe the coax into the old laptop somehow?
And it needs to be running what?
Then from the old laptop into my Linksys 802.11B router? Or do I need another kind of router.
I also happen to have an old Cisco Catalyst switch lying around, would throwing that into the mix somewhere help maybe?
I'm pretty computer savvy, but this kind of wireless networking is a little beyond me. And I've been out of the tech loop for about two and half years now.

Sorry to ask you guys to dumb this down for me.

So far it looks like with a little work and some know-how this could be doable though.