The answer is NO. I have tried it and it doesn't work because the wifi disconnects while you are locked. However, you can mimick sleeping your iPod (i.e. to save battery) by creating a black picture on paint (320 x 480). Load it up on your iPod/iPhone, set the lock time to never, brightness to minimum and find your picture. You will have a black screen which will obviously use up less battery power. It's not as efficient as locking your iPod but saves energy because a lot of it is wasted on screen brightness.