i have been using this. no need to really go into details here but if you want to try it out here is the link!
http://my.navizon.com/Webapps/UserAd...e=5B5E57585E5B
and it does have a map... you will have to sign up from the link and then go to
www.navizon.com from your phone to download the actual program. then just map the wifi and towers in your area. pretty cool! if you have any questions email me or pm me here!