If you don't have 20 gig of music yet, then why rush the install? If I were you, I'd Ebay the 12 gig now, and down the road a bit when you need more room, buy a more serious drive, like a 40. The money you get for a 12 today will probably buy you a 40 in a year.
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_____________________________ It's getting to be ri-god-damn-diculous.