The following is a description of a remote-control application for your NXT:
"NxtMgr is a utility that will allow you to control (your) Lego Mindstorms robots via Bluetooth. The program will allow you to define the port control, set the speed of different engines installed on the robot and the time of issuance of the order, among other possibilities.
To use NxtMgr, you need Palm OS 3.0"
The application costs 0.99USD and is available here in English and Spanish.
I haven't used the app and make no claim regarding it or its seller.