Review: Samsung UpStage
Incoming text messages are displayed full-screen on which ever side of the phone is currently active. Pressing the flip key will display them on the other side. If you want to scroll through your inbox, you can only do that on the media side. You can also start a new text on that side, but you'll have to turn the phone over rather quickly.
Because you have to use both sides of the phone to interact with most messaging features, we found ourselves completely skipping the texts we would normally send in favor of making a call.