subtraction library kit?

[mbracey]

I would appreciate any suggestions for a successful kit for making 
subtraction libraries.  The one available from Invitrogen doesn't
seem very appealing.  It seems that we recently saw one advertised
in the journals or in the mail that was based on avidin/biotin
and involved running the annealed mixture over a column and 
collecting the flow thru.  Any endorsements or warnings would 
be greatly appreciated.

Michael