Many UCSB guests can access the wireless network via eduroam. More information on eduroam can be found here:
http://www.ets.ucsb.edu/services/eduroam
If guests are visiting UCSB who do not have access to eduroam, a guest UCSBnetID can be requested using the information on the following page:
http://www.identity.ucsb.edu/customers/affiliates/