My ISP uses DHCP to assign my IP address. Thus, I cannot guarantee the IP address that the world sees me. How does the VPN client get to my private network in this situation?
When you setup the free 1 year service, one of the features is Dynamic DNS from ZoneAlarm. They will automatically assign you a unique (albeit ugly) Dynamic DNS Name. Mine for instance is gw801.myzonealarm.net.
On a similar note -- is there any way to request a Dynamic DNS name ? I have two Z100G's and was used to a DynDNS.org name of my choosing with my Linksys routers. gw801 and gw706x are not particularly easy to remember.