[Ernest_at_the_Beach]

What, exactly are you wanting to back up?

User Data,...or complete Operating System plus Data...

With Multiple machines and if backup is your user Data,...then Network access across all machines is very nice...

[Constitutionalist Conservative]

Yeah, I'm still leaning toward a network solution, because I've got a heckuva lot of user data on three machines to back up (not critical to back up the OS, but I might do that also).

My hopes have been revived by CharlesWayneCT's suggestion about a wireless data station (or network USB hub), which would allow me to buy a cheaper external USB hard drive, and connect it to the network through one of these devices.