Just saw this app posted over at Android Central. Figured you guys might be interested in it too. Has maps for 4G(sprint) CDMA(Sprint,verizon,ect) and GSM(AT&T)
Basically you run this app in the background(or whenever you feel like it) and users fill in the coverage maps by just using thier phones.

Thought you guys might be interested. Its Free. Here is the original post (credit where its due)
http://forum.androidcentral.com/android-applications/20008-sensorly-shows-where-4g-really-3g-too.html


Summary: The updated Sensorly app tells you:
• Do you actually have 4G and just don't know it?
• Who offers the best 3G coverage in your area?
• How accurate are the coverage maps?
Android|Central members are reporting 4G coverage in announced markets and many unannounced markets. San Fransisco, Los Angeles, Washington DC, Jacksonville, Nashville, Manhattan, St Louis, Chicago, Richmond, Denver, New York, and other markets have reported coverage in areas not on Sprint's maps. Some aren't even on the notification list.

There have been other apps like Antennas that can find 3G towers but how do you know where your 4G (and 3G) coverage really is?

Sensorly Map Viewer version 1.2.9 has just hit the market and can answer all of these questions. Sensorly users have been quietly mapping the real 4G coverage all across the US for weeks now. Sensorly automatically charts your coverage while you drive. This lets Sprint, Verizon, AT&T, T-Mobile, and international users keep their carriers honest with real 3G coverage charts on the Sensorly website. The maps on your phone are much higher resolution, to within 50 feet.

Version 1.2.9 is still free and brings a number of nice upgrades but the best is that in addition to showing 4G service in green, areas tested without 4G are now in blue. Has your area been tested? Just turn on the app as you drive and your results will automatically be compiled to the maps in a few hours. Sensorly will show you who really has the best coverage in your area and proves where the dead-spots really are, even block-by-block.

Note that the HTC One X reports 3G signal levels but only shows 4G as "On" or "Off." Also, as Sprint continues to test towers, you can expect unannounced cells to be off at times. Just search on "Sensorly" in the Android marketplace or download from AppBrain or their website.

Some suggested settings: Menu → More → Settings
• Turn screen on while scanning ON - otherwise it will not scan!
• Show legend and status ON - so you can see if you are collecting data.
• Scan WiFi networks OFF - unless you have public WiFi networks you want to scan
• Allow passive scanning OFF - when you are done so that Sensorly does not run when it is off.
• Also Menu → Map in background - to be able to keep mapping while using the phone for other things.

Go forth and chart the uncharted lands!

no clue. Just started using it. But I'm odd in that I am not worried about battery too much. I'm always at home, work or car, so charging is never an issue.

And of course you can always turn it off.

Me personally? I'll use it for a while until I have all the normal places I go mapped. Then just flip it on if I travel to a new area.

Just seems like a really cool project.