"There must be a way to grab the WAV files off my hard drive and using iTunes compress the files, store the compressed music in a directory on the drive, and then load my iPod with the compressed files."
Jeff, Heres one way. Open up iTunes so youre in your Library of uncompressed tunes. Go to iTunes Preferences. Under Pref:Importing, select your compression format. Under Pref:Advanced, change your iTunes music folder location to a new folder.
Your compressed tunes will be saved to this new location. Your uncompressed originals will remain where they are, and they will remain in your Library. The Library can point to tunes in multiple locations.
Select an original tune, or all your original tunes, go to the iTunes Advanced menu, and choose Convert Selection To [whatever compression format you chose will show in the menu]. iTunes will start making compressed copies of your originals. Both the originals and the compressed versions will show in the Library. So, youll have two of each tune youve converted.
At this point you could load your iPod. Go to the iTunes Edit menu and choose View Options. Check the box next to Kind. Then, in the iTunes window youll get a column that shows WAV or MPEG or AAC or whatever. You can sort on this column to separate your WAVs from your compressed tunes. Then you can select the whole group of compressed tunes and drag them over to your iPod.
What to do with the compressed doubles in your Library? You could just delete them (from the Library list, not from the hard drive), because if you need to access them again, you can always restore them to your Library by dragging song files or folders straight from your hard drive into the Library icon in your iTunes window. If you delete them, unless youve already reset your iTunes music folder location to its original location, iTunes also will ask you if you want to erase the tunes youre deleting from the iTunes music folder. Answer no, so that your folders of compressed tunes will not be deleted from the hard drive.
The key to all this is to be familiar with the Preferences menus. Each time you import or convert something, make sure you know what compression or lossless format Preferences is set to and which folder on your hard drive is currently designated the iTunes music folder.
Hope this helps. By the way, I like AAC 192 kbps for listening to the iPod through Sennheiser 580s. Thats where diminishing returns really kicks in for me. I feel kind of stingy about iPod disk space, however, and I know others who are less focused on conserving space would see that point of diminishing returns differently.