I'm writing this to cover these two scenarios:
1) You want to be able to listen and find out what is going on...
2) You want to be able to communicate with friends/family in the event the grid goes down
I don't want to get into personal details here but let's just say I have been in situations where the grid has been down so trust me when I said odds are your only working communication or finding out what is happening will be a radio/scanner in that situation.
Let's start with #2.
First off, nothing over the air is private! Everything can easily be picked up and monitored by the public (except cell phones) Cell phones can also be easily picked up and monitored by the government or the wireless providers or anyone with the right equipment or access.
Your choices are CB radio or FRS (family radio services) radio (those little walkie talkies you see at any store). Don't be fooled by any of the advertisements on those walkie talkies saying they're private or have private channels. If you really want to know what they're talking about it's something called CTCSS.
CB's can go further than the handhelds. I personally have tested CB's at more than 10 miles away. It all depends on your areas weather conditions, line of sight, many things. I've never had the FRS radios go anywhere near the distance they advertise. I wouldn't expect to get more than a quarter to half a mile out of them in an urban location.
For item #1 I still recommend the scanner mentioned (Uniden Compact APCO 25 Handheld Scanner BCD396XT). Looks like the price has gone down on Amazon to $399~
Before ordering anything I would recommend doing some Google searches for what frequencies your local police/fire/rescue use. It should also mention a trunking system (if any) or may mention a repeater.
There are 2 basic types of radio communication.
Simplex
and Duplex
Simplex is you transmitting on your radio talking to someone with another radio (CB's and FRS radios use simplex)
Duplex uses what's called a repeater (which is on a tower) So the radio transmits out and is picked up by the tower and the tower amplifies and sends back out the transmission. With repeaters you will see a frequency you listen to and something called an offset (for example + or -5) The offset is a second frequency close to the first one that is used to transmit. There are also tones associated with a repeater but for the purposes of listening (or scanning) you don't need to know anything about them.
Trunking systems also take advantage of a tower setup and duplex. I haven't done any research on this but based on how things have evolved where I live over the last 15 years I'm going to say pretty much every organization is making use of trunking systems and towers. Simplex is only a fall back if everything were to go down.
As well, I would very surprised if any organization is using analog anymore. Again, do some searches and see what people are saying. If anything, you might find your local police is in the process of moving from a duplex only setup to using a trunking system.
Trunking in a nutshell is software in the radio that leverages using multiple channels (or radio frequencies). It splits up the conversation so that someone tuned to say 155.55mhz might only pick up one word of the conversation.
With the scanner I recommend you will use your computer and some free software to program it. To search/download frequencies I recommend RadioReference. I think you can search for free to see what all they have for your area and it was about $15 for a 6 month subscription.
You don't need to keep the subscription... just use it to download all the frequencies you want and save them on your computer.
Scanners are awesome! I have quite a few crazy stories such as my life being saved and avoiding getting stopped by the police (while on a first date!) all because I pickup what is floating over the airwaves.
