Well, in my music library, I have 1026 songs, 2.5 days, 2:14:40:57 total time, 3.66 GB. I'd have a little more, but I just deleted most of one album because it sucked, lol. I have mostly 128 kbps mp3's, because I'm not an audiophile, but none under 128 because then you can really start to tell that it sucks.
In my entire library (which includes podcasts and videos), I have 1110 items, 2.7 days, 2:19:22:12 total time, 4.76 GB. Kinda defeats the purpose of having a 30GB iPod, but my laptop HDD is only 20GB so I have a backup of my computer on my iPod. Everything my computer could ever hold can fit on my iPod with 10GB to spare. 😀
I definitely don't win in the biggest iTunes library contest. I'm in the lower percentile I guess. 🙄