Some radio info
I have my amateur radio license, and use my HAM radio quite a bit in the backcountry (both handheld and a mobile unit in my truck).
One thing that I think is important to note, is the power output and type of antenna you have on your radio, regardless of what type of radio or frequency band you are using, will have a large impact on your range and ability to communicate.
For example: It's easy to say, "HAM radio is way better than CB/FRS, etc.." but that doesn't necessarily mean anything unless you specify what type of radio you are using. In general amateur radio has the capacity to be the best - due to the ability to transmit with higher power and possibility of utilizing a repeater network. However, a mobile CB radio with a true 1/4 wave antenna will transmit way farther than say a handheld VHF radio on the HAM band.
So, lets break it down:
1. FRS
-Only 1/2 watt transmit power
-Range: 1/2 mile up to 3 miles or so, depending on conditions
-UHF: 462 - 467 MHz
2. CB radio
-Only 4 watts transmit power
-Range: 2 to 10+ miles depending on conditions and antenna
-HF: 27 MHz
3. Amateur radio (HAM)
-Up to 50 watts transmit power (VHF 2 meter band)
-Range: Virtually unlimited. A HF radio can bounce a signal off the atmosphere and communicate half way around the globe with only a few watts of power - this type of equipment is generally set up in your house or garage and not in your vehicle though. The more common mobile VHF and UHF radios will transmit anywhere from 25 up to 75 miles. Again it all depends on your antenna and what the landscape is like. And if you can reach a repeater network, again your range will be virtually unlimited. (you can even make a call to a cell phone from your radio if you hit a repeater with an autopatch)
To sum up:
Don't go out and buy a cheap handheld HAM radio (like the UV5R linked in post # 8) and expect to communicate in any conditions.
I suggest you do little reading, definitely consider an amateur radio license, and when the time comes do a little research to find a radio/antenna combo that fits your budget and needs.
Personally, I use a Wouxun KG-UV6D dual band handheld, and a PowerWerx DB-750x dual band mobile with a Comet CA-2x4SR antenna (which is designed to work outside of the HAM band, because I primarily use the public service band for EMS and SAR). Plus the dual band mobile radio gives me access to the FRS/GMRS frequencies, as well as MURS and Airband AM.