I have used Airfoil on my iMac at home for a long time… a software program that allows for streaming music out to multiple rooms that have Airport Express devices hooked up to speakers. Airfoil by Rogue Amoeba is $25 for either Mac or PC keeps multiple rooms all in audio sync.
While looking at the latest Airfoil update, I noticed that Rogue Amoeba is now offering a free app for the iPhone and iPod Touch to act as a reciever. No longer is there a need to have your music pushed out to speakers that everyone in the house has to listen to. Instead, your iPhone or Touch can act as a reciever, plug in your headphones and you have the audio coming to you via your desktop. This is a nice little feature for those times you don’t want to have particular music or audiobooks loaded onto your iOS device.
The only limitation you have with Airfoil for iOS is the inability to choose what is playing via the handheld, your listening to whatever is qued up on the desktop.
One reason I may not have noticed the Airfoil app release was how successful Here File File for the iPhone has been for me. It isn’t a free app on the iPhone but the desktop side is free. Major differences is that Here File File is a 1:1 relationship with the desktop so your not steaming music out to multiple rooms/devices. On the other hand, you are able to choose what your listening to (or watching) via your handheld.
It comes down to if you using your iPhone as a remote speaker for your desktop or your looking to control the audio/video streaming to you.