there are several types of two way radios out there now. You have CB, FRS, GMRS, and varuios ham ranges such as 2M, 10M, etc.

FRS and GMRS are the most popular now, GMRS leagally requires a license while FRS does not, but as I and others have found FRS quicly looses range when in any kind of wooded area. There are combination FRS/GMRS radios which a lot of people buy and use without the GMRS license, sometimes without even knowing they need it.

HAM radios are a bit more investment and require passing of a test.

CB while it died off with use of cell phones seems to be coming back in popularity a bit, I see at least one post a week on some of the automotive boards with someone wanting to put a cb in their truck for talking to others while on the trail. I had a couple friends with them laying in their garage like I so we pulled ours out and started using them again.