Most of the time I use my iPod to transport my music between home and work so it acts more like a portable hard drive than an MP3 player. I just load up iTunes at work, hook up the iPod, and I can browse and play music from the iPod just as if it were loaded on the PC.
I do recommend that you use a firewire or USB 2.0 connection though. I was originally using a USB 1.1 and while the music would play just fine, the iTunes interface would constantly freeze up for seconds at a time. It was really annoying.