answer:By “memory” you mean hard drive space, not RAM, right? I use (and love) a Western Digital MyBook 1TB drive. It’s dedicated for use as a Time Machine backup, but one could use it for anything. Easiest would probably be Apple’s Time Capsule drive – it’s fully networkable (wireless) and also serves as a network extender – you can plus printers into it, non-wireless computers can connect via its router ports, etc. Pricey, but nicey.