I actually spent a little bit more and bought a time capsule - I wasn't really looking for an n router (I had been using my mac to create my wireless network), but I wanted to start backing up regular (after nearly loosing 160 gigs of family stuff, including photos), and it seemed like a good way to go. A bit more (300 before discount) than just buying a 500 gig hard drive for sure, but I've got a rock solid n router and gigabit ethernet for anything I hook up with copper.
and I've got a lot more peace of mind about having future hard drive problems, and not having to spend a week of my life trying desperately to recover lost data without causing further damage to the drive...
Just my .02. It hurt the wallet for a few minutes to purchase it, but I forgot all about that once I got it home and set up. Works like a champ, easy to use, works perfect on both the mac and windows, and you can use the drive as an NAS as well. Still have the USB port open on the back if I want to share more than just the printer I have hooked up to the mac (which I'll be doing next week), or add an extra hard drive to the network for storage.
great solution, IMHO.