I was interested in getting a 20gb iPod and then heard about Creative's Zen...

How well does it compare? Can it be only used with a PC, or is it also Mac compatible?

Any info / advice much appreciated!

Cheers :D

Creative's zens... I think they are only compatible with Windows XP. If you have a MAC and you want to buy a Creative Zen, you should take a look at this. It is called XNJB and I think this is the only way to make creative mp3's work with MACs.
If I were you I would buy an iPod. It would be much easier, you wouldn't have to buy a XNJB
And ,trust me, iPods are good. I love mine.