Are you travelling outside of your country? If you're with a group of people and get separated, cell phones are a blessing to have. However, roaming charges in the US and internationally can add up quickly – not to mention any text messaging you send or receive can be calculated at international fees as well! There are a few options to relieve the stress of a massive phone bill when you return. If you need to stay in contact with your group, you can purchase pay-as-you-go phones from a number of providers, such as Net10. Through your cell phone provider, you may be able to add international/US minutes and texting to your phone for the duration of your journey. There's also the option of purchasing a SIM card for your smart phone for travel in the States that would allow you to add pay-as-you-go minutes as well.
If you're going to be somewhere for an extended period of time and don't want to be taking your cell phone, there is the option of communicating through services, such as Skype, via computers with microphones – you can video chat as well if you have a webcam on the computer. If you're taking your laptop with you, scope out potential internet cafes, or places with wireless internet that you can hook into and chat with your friends and family that way. Best of all, Skype is free if both users have computers, and extremely cheap if you're calling a landline from your computer.
One area that we recommend you investigate is if your carrier has an option for you to have them disable your roaming ability, some carriers allow you to stop and start data roaming ahead of your departure. Sometimes, even if you have set your phone programming to not allow data roaming, you will get dinged. In addition, even if you have Wi-Fi where you are going, you must disable your data roaming or you will have a nasty surprise.