Currently I have an iMac, MacBook Pro, MacMini and an AppleTV all networked using an AEBSn. The advice that I need is that I'm thinking of purchasing two external hard dives, one to use for time machine that will be connected to the AEBSn via USB so that all of the computers can be backed up. The other will be connected to the iMac which is the main computer (via firewire) and be used for my iTunes and iPhoto libraries which are getting rather large. Is this the best configuration or should I be doing something else? Cost is not a big issue, however I would like to keep it as low as possible.