So I was playing around with my iPhone and I found something out. Here goes. So, I downloaded a Youtube music video into my iPhone. As you know, OS 2.0 onwards allows you to watch videos in your iPod function. But, you can't turn it off while the video is running. Here's a tip on how to turn it off, it you just want to hear sound without seeing the video. 1) While your video is playing, use shuffle to skip to the next audio track. 2) When it skips to an audio track, turn your iPhone to sleep mode. 3) Wake iPhone and double-click the home button twice to bring up the music player. 4) Press rewind twice to get back to the video you were watching. 5) Now, it is stationary and you only hear audio. This way, you can turn it off. Hope it works and helps!