Is there a way to turn the cell phone radios 100% off and only have WiFi on? I'm currently up in the mountains and am roaming, but there's WiFi, so I don't want the 2/3/4G radios to be on.

Also, does anyone know how roaming with Sprint works? Would I get charged for texting or making calls? Thanks.

EDIT: Turns out I was doing it right, but the WiFi wasn't working because I assigned my phone a static IP for my home network, but the IP was out of range on the current network I'm using.

To use only the wifi do the following:

1. Hold down the power button for ~2 seconds
2. Enable Airplane Mode.
3. Enable WiFi and connect to your network

If the WiFi isn't working, make sure you weren't doing what I did with the static IP address.

1. Open SettingsWireless & network settings>WiFi Settings
2. Press the menu button and click advanced
3. Untick "Use static IP"