I use a 60GB iPod but not for MP3s (for the reasons already stated). I use uncompressedf file format (CD "Quality") which will only allow me to carry 3,000 tunes vs. 15,000. Of course, I rip my own files, since the download community is MP3 based.
The other nice feature of the iPod is that it has an optical digital out, which I can plug into my outboard DAC or straight into my Meridian gear. It make a nice jukebox!