See Amateur Radio (Ham):

1. Distance depends on terrain and antenna. A CB with a car antenna can go up to 5 miles between cars with antennas. A handheld CB may be lucky to go 1 mi.

2. CB can go up to 12 watts for SSB
HF - High Frequency, VHF - Very High Frequency, UHF - Ultra High Frrequency

CB Radio 27 MHz Citizens Band (40 channels) (2-Way Personal Radio/Walkie-Talkie)
Popular to talk with other jeeps in a carivan.

CB radios have the longest range of any of the different types of radio services, but only if used with a good antenna. And that presents as the major weakness of CB radios for most casual applications - the ideal length for a CB radio antenna is about 15 feet!

Expect two to five miles range between two cars, and as many as ten or more miles between a base station and a car.

But CB radios are probably your worst solution for communications between two people using hand-held portable radios with short antennas.

(40 vs 80 channel, handheld vs mounted?)
Range can be improved with
1. SSB option.
2. Vehicle-mounted units with matched cabling and antenna.
Handheld 40 channel $80
Compact Remote-Mount (Cobara 75 WX S) $120 + antenna & cable $15-30

FRS Family Radio Service (14 channel + 38 privacy codes, 1/2 watt (500mW), walkie talkie no license)
They advertise 2 miles, but in semi-open ground, you'll get about half a mile of range, sometimes less (especially if things block the line of sight between you).

GMRS General Mobile Radio Service (8 channels 5 watts max., external antenna optional, license req. [$85/5 years])
2 Watt units advertise 4-8 miles, but in testing at The Travel Insider they never got more than 0.7 mi. with a 2 watt unit with a built in antenna.
The Motorola Talkabout MR350R advertises 35 miles from mountain to valley, 9 miles over water and 2 miles in urban settings. One user reported 3 miles in the woods and just over 1 mile in a residential development.

Consumer Reports tests of GMRS worked well in a mall and went up to 1.5 mile in a suburban neighborhood.

3 watt GMRS radios advertise 8 miles on land and 10 mi. over open water;
5 watt units advertise 10-14 mi. distances.

A repeater is one additional item that can be added to a GMRS system to increase range.

Many of the combined FRS/GMRS radios only use 1/2 watt for both services
See: wireless.fcc.gov/services/personal/generalmobile/

MURS - Multi-Use Radio Service (150 MHz) - New; similar to FRS, GMRS

Amateur Radio operators or "Hams" have the added advantage of using repeaters to increase the range of reliable contacts. There are thousands of amateur radio repeaters located across the country and they are often located on top of the mountain ranges near off highway vehicle trails. Some repeaters have autopatch capabilities, which means you can make telephone calls from your radio.

Range Guidelines

Table at Kenwood Two Way Radios

Terrain	1/2 Watt FRS Family Radios	1 Watt UHF GMRS Radios	2 Watt UHF GMRS Radios	2 Watt MURS
Outside Clear Flat Terrain	1.5 to 2 miles	2 to 3 miles	3 to 4 miles	3 to 5 miles
Suburban Neighborhoods	1 to 1.5 miles	1 to 2 miles	1.5 to 2 miles	1.5 to 3 miles
Urban Areas	1/2 to 1 mile	1/2 to 1.5 miles	1 to 1.5 miles	1 to 1.5 miles
Inside Buildings or Malls	1/2 mile or 5 floors	1/2 to 3/4 mile 15 floors	1 mile 20 floors	1/2 mile 10 Floors
Between Buildings or Houses	1/8 to 1/2 mile	1/2 to 1 mile	1/2 to 2 miles	1 to 3 miles
Woodlands, Moderate Vegetation	1 to 1.5 miles	1 to 2 miles	1.5 to 2 miles	2 to 3 miles
Woodlands, Thick Vegetation	1/2 to 1 mile	1/2 to 1.5 miles	1 to 1.5 miles	1.5 to 2 miles

On-line suppliers:

Dealers:
Chickenlips CB's & Stuff 8196 Belvedere Avenue, Sacramento 916 451-7530, 8-4:30 Tu. - Sa. (Going out of business Jan. 2006)

Sacramento 49er Travel Plz (Truck Stop) (916) 927-4774 - CB
2828 El Centro Rd @ W. El Camino and I-80 Sacramento, CA

CB Shop, Airtime Communications, 775 359-4841, Petro Alamo Truck Stop, Sparks, NV , Sparks Blvd. Exit S. from I-80

Ham Radio Outlet (800) 854-6046 / (510) 534-5757 2210 Livingston St., Oakland, CA. 94606

BARRY ELECTRONICS CORP (212) 925 7000
540 Broadway New York, NY 10012

CB
Newport Bay Ltd. (732) 257-9097
725 State Route 18 (at Race Track Rd. 3 mi. f/ Rt. 1, past K-Mart)
East Brunswick,

Manufacturers:
GigaParts
Amateur radio division of Vertex (yaesu.com/)

See:
Personal Radio in hobbies
Amateur Radio Products
Amateur Radio Info and Installation in Hobbies
Two-Way Radios: Find, Compare, @ Yahoo! Shopping
Antenna Types and Installation
Electromagnetic Spectrum
Antenna Connectors - Plugs - cables
Industrial/Business Radio at the FCC
Emergency Communications, Satellite Phone,
Amateur (Ham) and CB Radio at Lake Tahoe