Check out the link below

http://openerpmanagementsystem.blogspot.jp/2012/02/configuring-ldap-authentication-with.html

I downloaded the openLDAP virtualbox version from turnkeylinux.org, import it into virtualbox.

after that add a new group names people, so that i got ou=people, and add an user under ou=people.

then i follow the setting from this link http://www.zbeanztech.com/blog/can-joomla-users-login-openerp-using-ldap

below are some setting i copy from that link:

OpenERP-LDAP

 6.Install python package,otherwise users_ldap module in openerp will not function
            sudo apt-get install python-ldap

 7.Install users_ldap module in the openerp which comes by default with openerp-server addons

 8.Configuration at the openerp side,
       "Administration-->Companies-->Companies",Your company profile and enter following details in ldap parametres
          LDAP Server Address : your machine IP (127.0.0.1 <-if ldap running on the same server)
          LDAP Server Port   : 389
         LDAP Bind Dn   :   cn=admin,dc=example,dc=com (if you had changed dc component then enter the same here and for followings)
         LDAP password  :   Your admin ldap password
         LDAP Base      :   ou=people,dc=example,dc=com        <-- change 'dc' here
         LDAP filter    :  (uid=%s)
         create user    : checked
         Model User     : demo user
         sequence      :  10

then you can login if your ldap user is exist in openERP, but got ERROR if the new user your create in openLDAP but not in openERP, hope some one can solve this problem.

Thank you.

best regards