Oops. A couple of people beat me to it, while I was drafting a lenghthy reply. Oh, well, here it is anyway:
Have you considered FRS radios?
Here's my story:
Several years ago I bought a couple of Cobra handheld CBs for caravanning. I ended up buying external, mag-mount antennas b/c the low-freq CB signal doesn't penetrate the auto glass very well (get's trapped inside the cab). With just the 'rubber ducky' antenna you can talk to someone a few feet away, but not sufficient for vehicle-to-vehicle.
Then I bought cigarette lighter plugs for them because they went through the 6 AA's so fast.
Then because of the cords hanging off of them, I bought hand-held mics.
And, of course, I bought two of everything because I caravanned with different people and need a 'loaner.'
I quit using 'em, partly because having to set everything up was a pain, but mostly because there are so many idiots out there with CBs that just want to mess with you. While we were having a friendly conversation, idiots would burst in with profanity, insults, or just garbled mumbo-jumbo. I guess they thought it was funny.
In the last couple of years I've been using FRS (Family Radio Service) radios. They are much higher frequency, so work well between two cars with just the built-in antenna. I think that they have slightly better range just using the built-in antennas than the old CBs did with external antennas. They are also much lighter and more convenient than the old handheld CBs. Oh, and the three AAs that they use last a whole lot longer than the 6 AAs the CBs ate.
FRS radios also typically have what they call 'security codes' that can be used to keep the idiots at bay.
Further reading for anyone interested:
FWIW, I think 'security codes' is a misnomer, because they don't provide any security; what you say on the radio is still broadcast so that anyone with a radio or scanner can hear it. It's not like its encrypted or something.
What they do, instead, is allow one radio to only 'hear' other radios that are currently using the same security code. 'Selective Hearing' would be a better name for it.
It is a handy feature for keeping the idiots at bay, but don't assume that it provides any sort of security. Don't say anything on any radio that you might later regret.
Also, be aware that many radios provide 22 channels, but if you read the fine print, the lower channels (1-14) are FRS, and the upper channels (15-22) are GMRS (Ground Mobile Radio Service). You are supposed to have an FCC-issued license to use the GMRS channels, but that fact isn't always obvious when you buy the radios.
