Hi, I have a Linksys WRT54G wireless-G router, and I have tried every # written on the back of the unit for a pass word to give me Wi-Fi access for my Iphone. Is the password written on the unit? And if so where, thanks in advance.

Normally you would gain access to the router through a computer or laptop by direct connection. Once inside the router then you can bring up the access codes and then enter them into Iphone as needed.

It takes a hardline and default address to get into the router.

The initial password is normally printed at the bottom of the router. Most likely the password has been changed.
Log into the router by clicking here -> http://192.168.1.1

The username and password is normally admin/admin or admin/password.

Browse through the links for wireless settings.