Best solution imo is a linux based nas/router eg NSLU2, WRT's, bubba, Thecus n****, linkstation pro, asus wl500gp etc etc, a lot have hacked firmwares or support debian based distros offering ext3 and/or full ntfs read/write.
With the added bonus of having a very cheap and energy efficient server/download/bittorrent box.
Downside is you'll have to get your hands dirty getting it set up.