I tend to disagree. Many routers today support UPnP, which can be used universally to map ports, regardless of the router's origin.

For one example, see "Using UPnP for Programmatic Port Forwardings and NAT Traversal" at http://www.codeproject.com/KB/IP/PortForward.aspx

With respect to another issue that's difficult for novice end users, it is also difficult for them to remember public IP numbers, rather than alpha names, and the public IP numbers often change anyway if your ISP assigns a dynamic IP each time you log on. For this, I would recommend a dynamic DNS service (DDNS). Search here for DDNS and you will find a few providers, many of which are free.

Using DDNS, your end-users will be able to type a name like tophat.yi.org, instead of remembering an IP number.

Mike