Re: touch sensor in virtual world
This is not currently possible. However, you can use the either the NXT's buttons or the buttons on the VEX LCD screen attachment (depending on which platform you're using) for this purpose.
After you Compile and Download your program, select Robot>>Debugger Windows>> and then either NXT Remote Screen or VEX Remote Screen.
See here for documentation on how to use the NXT buttons in your code: http://www.robotc.net/support/nxt/MindstormsWebHelp/index.htm#page=nxt_functions/buttons/Buttons.htm
See here for documentation on how to use the VEX buttons in your code: http://www.robotc.net/forums/viewtopic.php?f=53&t=3452
Alternately, if you have a USB joystick or gamepad, you could use a joystick button to do the same thing.