When we travel to Disney we RENT 2-way radios (Nextel telephones), however the company that we always used went out of business so I searched and searched and searched some more and found another company that rent radios. Thier website is allradioinc.com.
They are VERY reasonable in price and you don't have to worry about getting a signal - you can communicate through the state of Florida!! They are used just like a "walkie-talkie". The only people that you will be communicating with are people in your group and your phone has a "call sign" on it. We use Disney characters as our call signs.
You can rent as many as you need. Most walkie-talkies that you purchase come in pairs, but if you need three you would need to purchase another set, with these you just rent how ever many that you need.
For us this is the best way to go - there is an expense but sooo worth it when communicating with others in your group in WDW.
Just a thought!!
Lisa