At work we're trying to set up a bunch of users on laptops with directory-based authentication and home directories. The trouble we're running into is that these laptops are all wireless, and on OS X, airport doesn't start until a user logs in. Therefore the machine can't see the authentication directory on the network until a local user has logged in and out again.

We need some way to get OS X to join a trusted wireless network before a user logs into the system – anyone have experience with this?

Tried so far: Mac OS X Hints and Google.