Nice filter string for importing profiles

(&(mailnickname=*)(|(&(objectCategory=person)(objectClass=user)(!(homeMDB=*))(!(msExchHomeServerName=*)))(&(objectCategory=person)(objectClass=user)(|(homeMDB=*)(msExchHomeServerName=*))))((!userAccountControl:1.2.840.113556.1.4.803:=2))(showInAddressBook=*))

Original article here.