Transfering music from external hard drive to iphone (without copying to disk) I have a large collection of mp3s (a backup of my old itunes from another computer) and I want to copy this to my new IPhone. 

Trouble is that my Mac is almost out of HD space, so I somehow want to copy the music directly from the external disk to the iPhone. I assume I can't do that from iTunes? Any ideas?
You can change the location of your iTunes library to be on that external HD. And then add those songs and sync your phone.

The preference in questions is in iTunes Preferences > Advanced and the top option allows you to choose the location of your iTunes library