I would like to use a list from one site as a look up for another site. Can I do this with out using code. Only use OOTB or Designer? Or is there a better way?
Under similar constraints in MOSS, my method has been to create a list at some "top level" site. Then, at that site, create a Site Column that is a lookup to the list. Site Columns are inherited downward so, in any site below that site, you can select "add from existing site columns" and now you've got a cross-site lookup without even needing designer.
In 2010, we're mostly replacing this approach with managed metadata.