Airfoil
Rogue Amoeba have released a free iPhone app (the creatively title Airfoil Speakers Touch) which turns their excellent Mac/PC desktop application Airfoil into a must-have.
Airfoil allows you to transmit the audio from any application on your laptop to the sound output of one of Apple's Airport Express routers. Indispensable for listening to Spotify without a dozen metres of cable tying you to the stereo.
If you're interested enough to still be reading, Airfoil Speakers Touch does away with the need for an Airport Express altogether, by turning your iPhone/iPod Touch into a receiver for the program to transmit to. Now you can sit your phone on top of the stereo and run a cable out of the line-out of the phone and into the line-in on your stereo while you pick your tunes from the comfort of a laptop on the sofa.
1st May 2009 - Tumblr