Iphone audio output

[hehe299792458]

With iOS 4.x, how do I switch between outputting audio to a bluetooth headset and the built in speaker?

 

[mikey4020]

I believe if you go into the iPod app then where the volume is there will be a bluetooth icon next to the slider. Tap this and a menu should come up asking you to select your audio source. This is what I do in my car to switch between bluetooth audio out and headphone jack out.