Download Signal 1.1. from here: Mac, Windows
Double click the downloaded file to extract its contents. On a mac you will extract an application called Signal.
Drag the Signal application you just extracted into your Applications folder.
Double click the Signal application to launch it.
A window will popup on your screen with an Http address. Take note of this address. You can now click the Hide button to hide the application.
Now on your iPhone press to launch Safari from your SpringBoard.
Press to select the address bar and enter the Http address we were just provided in Step Five.
NOTE***: Notice the Http address we are using is your computers IP Address. A far better solution is to use your computer's host name in place of the IP Address, since your IP could change. You can find this by selecting Sharing from your System Preferences. In my case my host name is iclarifieds-macbook.local. Therefore, the address I would have put into safari is http://iclarifieds-macbook.local:3569
Notice you are now presented with an iTunes interface. Lets make a Bookmarklet so we can access this interface quickly from the SpringBoard. Press the + button at the bottom of the screen.
Press the large Add to Home Screen button that appears.
Name the Bookmarklet then press the Add button at the top right of the screen.
Notice a new icon is present on the SpringBoard for Signal. Press the icon to launch it.
Now press the Music Note at the top left to access your iTunes Library!
You browse your Music or Movie library and anything you select will play right on your computer!!!