Andy reminds me that a relatively simple idea (I think it was David’s at RepoCamp) for the OAI-ORE Challenge would be to create a tool that transformed OAI-ORE resource maps expressed as Atom into Google Site Maps. This would allow “repositories” that exposed their “objects” as resource maps, to easily be crawled by Google and others.
It would also be useful to demonstrate what value-add OAI-ORE resource maps give you: to answer the question of why not just generate the site map and be done with it. I think there definitely are advantages, such as being able to identify compound objects or aggregations of web resources, and then make assertions about them (a.k.a. attach metadata to them).