Several manufactures produce handheld tranceivers that can communicate on the International Aircraft Communication Band. (Referred to as the Com Band) It is for voice communication, and runs from about 118-137MHz. The radios operate on VHF FM, and the quality of communication is surprisingly high. The size of these units has dropped over the past 10 years to make them very reasonable to carry. You do not need a license to operate them from your aircraft in the US. However, to transmit from ground to aircraft, you need to operate under an FCC ground station authorization. Typically, people granted that would be associated with aviation services like airports, pilot training businesses, chase crews for ballooning/soaring. This is similar to Marine radios, which can be used without license on your recreational boat while it's on the water, but, can't be used on land without a special license.

The handhelds will often also have other features, like navigation band (108-118MHz) for VOR, as an example. They will usually have the weather channels included in coverage, and since they are based on Amateur Radio transceivers, many can be modified to cover multiple bands. (You have to have an Amateur Radio license.)

One company that produces some very reliable products in this area is ICOM. They also provide police/fire radios, amateur radios, marine electronics, etc. I have had several of their radios, which perform very reliably. I understand from friends that Yaesu (now called Vertex Standard I think) produces a very nice combination unit that covers the aviation and amateur VHF bands and US weather channels in one very small unit for about $400.