OpenBSD could be used to setup a private network in your residence, but the OpenBSD system itself would still associate with the college router the same way as other students do, i.e: encrypted wireless via WEP or WPA?
We don't know enough about your setup, but establishing a secure tunnel with that college router is probably not an option...
It would be possible to securely tunnel connections to somewhere outside of the college.. a friends house?
Anyway, hope that helps.