How do I use the "OR" function?

Hi Guys,

My company is using an ldap query to populate our online phone directory.

We recently added "Contacts" to AD to represent our meeting room numbers and fax machines etc...

This is our current query string:
(&(objectClass=user)(samaccounttype=805306368)(objectCategory=person)(memberOf=CN=security group,CN=Users,DC=domainname,DC=com)(cn=*)(!(cn=* PA))(!(userAccountControl:1.2.840.113556.1.4.803:=2))(!(userAccountControl=65536)))

Basically, how do we add an "OR" objectClass=contact to the end of this?
The contact does not need any of the filter criteria from above, just to simply be a contact.

Thanks,
Chris