Use your Android device as a spy tool!
Just run app, put it in secret place, send SMS - it will record audio around your phone!
Then you'll find audio file on SD card, "Data" folder, "audio.3gp".
To stop running application and record audio, use Menu button.
Link to app https://market.android.com/details?id=org.ivakin.silentspy
Need more functions? Send feedback to firstname.lastname@example.org !