How do I copy all my music from my old iPod Touch to the computer/iTunes on Windows 7, so I can put it on my new iPod Touch?
There's a free application called SharePod specifically designed to do this (to transfer music from an iPod to a PC).
I use SharePod as a convenient way to copy mp3s that I own from my home PC (where I originally copied the music from PC to iPod, using iTunes) to my work PC.
Update January 2014 - As of the latest version, SharePod v4, it looks like SharePod is no longer free, unfortunately.
My Computer, right-click on your device, click
Copy, navigate to the place on your HD that you want the files, right-click, and click
You can also paste the data directly onto the new device, instead of using your HD.
Note: This doesn't work with iPod Touch, only with older iPods.