Easy. How's your budget? Solution #1 -- and my own choice -- is a network hub: click here This is great for getting access to whatever external HDD I happen to plug into it, it includes a print server, and it works as a regular USB hub. Solution #2 is to replace your current external HDD with a NAS, some of which have become very good value, relatively speaking: click here Solution #3 is cheap but potentially tricky, particularly with certain operating systems (which you have not specified): you may be able to map it as a network drive and thus include it in your shares. But that is not something that I have ever had to dabble in, with the hub on one network and a NAS on the other.