Very quick example of how I setup mine:
1a. Setup your apex with a unique static internal IP address. Such as 192.168.1.30 (make sure it matches the same ip range as your computers). You can use the 'ipconfig /all' command to find out what your computer's internal IP address is.
1b. Make sure it's plugged into your router/switch with an ethernet cable.
1c. Go to
http://192.168.1.30/ from your home PC and the apex login screen should appear.
2. Now login to your router setup screen. Setup port forwarding on your router. Example: On your router, port forward (external) port 8080 to (internal) 192.167.1.30 port 80.
3. Setup DDNS (Dynamic DNS) on your router, most linksys support this. Usually you just tell it that you're using dyndns.com, what your username and password are for dyndns.com, and what the 'alias' is. Example: johnsmith.dyndns.org.
4. Now from work or other peoples houses (or even better: iphone or blackberry on 3G), go to:
http://johnsmith.dyndns.org:8080/ and the apex login screen should appear.
P.S. Then go get an iPhone and use the AquaNotes app to monitor your tank remotely!