You may want to install wireless-tools which includes iwconfig (it will be in /sbin/) which will tell you everything you wanted to know about your AP and more.

It is not auto-updating, so it won't tell you signal strength as you move around, but it will give you good info about the AP. You need to run it from an xterm.

If you want to war-walk (search for wireless APs) then I would suggest you search the forum for Kismet and how to install it. It works very nicely on the N800 (again in the terminal).

I hope this helps,

Craig...