Detecting Range of Access Point

Okay I'm currently visiting someone in Hawaii, and I'm just waiting around in a house with my laptop. There are several networks available, only one of which is unsecured. I've been able to connect to it but it's a very very low signal so it goes out every few minutes, then I have to keep trying to reconnect to it.

My question is: Where can I find a program, or what method can I use, to detect if I am getting closer to a wireless access point? For example, I want to know if I move 10 feet west if that strengthened my signal (albeit very slightly). Unfortunately the 5 bar system that windows uses to denote signal strength does not allow that type of detail. One bar might equate to tens of feet closer (which I can't really do). I just need to slightly strengthen my signal. Sure I could just walk around randomly but it would be really awesome if there was a program that could in essence detect the direction of a wireless access and allow me to move closer to that access point very accurately.

Thanks in advance for your knowledge, wisdom, and help.

 

Which OS?
Netstumbler or inSSIDer.

 

http://www.netstumbler.com/

 

I'm running Windows Vista 64 bit