I've been reading about the Time Capsule and I'm still a little confused on the device. It is my understanding that the Time Capsule can be used as wireless router and backup storage device. I already have a wireless router that I'm happy w/ at home and I only wish to use the Time Capsule for its backup storage capabilities. Is this possible? If so, how? Does it make sense to use the Time Capsule this way or should I look for a different NAS drive to serve my purposes?