www.BBScanner.comI'm sitting at my desk right now listening to the FDNY radio channel on my Blackberry. Last night I listened to the Nassau County Police while I cleaned up after dinner. The radio feed can be sent through the speakerphone speaker, wired headphones, or even out to a bluetooth earpiece.
While I doubt the service would work in a major disaster scenario (it uses a large amount of wireless bandwidth to download the audio feed), it might be useful in more limited situations, or to get a headsup on what's going on around you before things get out of hand.
Plus, it's kind of fun.
Downsides are that it uses your batteries pretty fast, and it's not a true scanner functionality as you need to choose one channel to listen to. It will try and determine your current location and suggest interesting things to listen to where you are.
I believe that there is a similar app for Iphones, and probably other devices as well. Free seven day trial, $4.99 to buy after that.
No connection with the company, just a satisfied user (so far).