How add home LaCie NAS to Finder sidebar on work iMac?
You can use this: http://www.chaoticsoftware.com/ProductPages/NetworkBeacon.html to create a sidebar icon on your Mac that links up to some address and port elsewhere.  Keep in mind it will show up regardless of whether it connects successfully or not, so don't take the appearance of your device in the sidebar to mean it's actually available.

A quick sample configuration: I have a VPN I can use to tunnel back into my home network.  Once I'm connected I can start Network Beacon with the following settings, to get my server to show up in my sidebar and for me to get access to the files:



Where the service name is just how it shows up in the sidebar, the service type is "AFP over TCP" - there's a bunch of other services you can choose from, the port number is relatively obvious, and important if you're using port forwarding instead of something like VPN, and then the host proxy information is the hostname and IP address of the device you're connecting to.