Best port for Juggernaut on a public website

Railsters:

The web has "matured" to the point where most slack-jawed users do have a firewall and don't know how to configure it.

Juggernaut requires a non-80 port. What's the best port for it, to improve the odds that anyone can get to it without learning how to be systems administrators?

Railsters:

The web has "matured" to the point where most slack-jawed users do have a
firewall and don't know how to configure it.

Juggernaut requires a non-80 port. What's the best port for it, to improve
the odds that anyone can get to it without learning how to be systems
administrators?