SASL GSSAPI and JDK1.5 Sample

Does anyone have a working example of a secure exchange between a client
and server with the new SASL and GSSAPI using the new JDK 1.5?  I have
access to LDAP with the old 1.4 libraries and the JNDI access with SASL,
but I just cannot get the purse SASL and GSSAPI working between a simple
SASL client and server.  Also, does anyone have a working example of the
call back handler that makes use of the new AuthorizeCallback() ?  I
suspect this is part of my problem.