Two way radios or walkie talkies are regulated the the Federal Communications Commission. The FCC decides what frequencies a two way radio has access to and how powerful said radios can be. Frequencies are grouped together based on use and one such group are the MURS frequencies. The MURS band was created in 2000 as a license free private two way radio communication tool. Two Way Radios using MURS are supposed to be 2 Watts and use the following frequencies.
154.570 Traditionally known as the Blue Dot Frequency
154.600 Traditionally know as the Green Dot Frequency
You'll find MURS Two Way Radios in use across the United States as well as local MURS frequency repeater clubs. Wal-Mart and Sam's Club are the largest user of MURS two way radios in the United States. Occassionally, you'll find a fast food restaurant still using MURS frequencies for their driver through system. MURS two way radios are VHF.
To learn more about the Federal Communication Commissions regulations for MURS two way radios visit the MURS Page on the FCC website.