NAS for MAC and Windows

So I haven't got to play with my new Air for the last few days.  I had a business trip and had to shop around for a backup storage option.  80Gb is not a lot and when shipped the Air takes up about 25Gb just for all the stuff they put on the HD.  Initially, I thought I would go with a mini-drive.  A fellow Mac enthusiast recommended the WD 250Gb miniHD from Costco.  Prices really have come down.  That mini is about $2 per Gb.  However, I also contemplated some sort of NAS solution so that I can store on 1 drive between a Mac and Windows based PC.  

I decided to get the NAS.  I went to Fry's and picked up the Maxtor Shared Storage II - 1Tb.  It was a heck of a time trying to get the network to recognize the device.  After a final reset on the Maxtor, I achieved success.  

A part of me thinks that I picked up a unit that was returned.  

I wasn't completely sure given that there was not a return label on the package.  However, that doesn't mean Fry's didn't re-package it.  After opening the unit, it looked fine even though I still felt it was a return.  So far it is working fine...we'll see.  The setup 

process was fairly easy once the unit was recognized.  As of this post, I am transferring files, including iTunes library.  Both the Mac and Windows PC can see the same files.  The one test will be whether or not I can point the Mac and PC to the one iTunes library file.