I have Googled this every which way, but wound up with no results, so I'm turning to AMA.

How do you move music from your iPod onto your iTunes library, on a mac, without downloading any programs?

I did this before sometime around a year ago, but for the life of me I cant' recall how I did it, and I can't seem to find the how-to article that guided me through it.  I think the idea was to get the music files from the iPod onto your computer and then add them to the iTunes library, but I have no clue how to do this.

Any ideas?