If you have Windows 2000 Server or Windows Server 2003 you can use the Internet Authentication Service (IAS) as a RADIUS server. Won't cost you any more for the software, it's already in there. Just some time is all that's needed to configure it.
You can link it to Active Directory so that your network login name and password also works on the routers and switches. Only one password to remember! And instant access to enable mode, too, if that's how you set it up.
Change the password on your Active Directory user account, then the new password is what you will need to log into any of your routers/switches.
Need to give someone else's login name access to your routers/switches while you're on vacation? Easy enough to do, just create an Active Directory acount for them (if they don't already have one) and put them in a specific RADIUS-related group. Now they have access to all the network devices, too. And you can control whether it is enable mode (read-write) access, or non-privileged user (read-only) access.
All you need to do is configure AAA on your routers and switches, and point them to the IP address(es) of the RADIUS server(s) they should talk to. Once that's done you're all set.
You can also configure local user names and passwords on the routers and switches as backup, in case the network device can't communicate with the RADIUS server.
