Kregan on here bought a cheap mp3 player and modified it with a simple switch that was attached to the transmitter. Simply tap your finger and the next manuever is heard in your earbud. Uses a free application on your computer- you type in what you want to hear and it produces a .wav file that you convert to .mp3 for each manuever in the voice of your choice. Slick and inexpensive- exactly what you are looking for.

Here is a post about it with some pics and info:

http://www.rcuniverse.com/forum/m_45...tm.htm#4604129