Google Co-op seems to be one of those Google features where it might take some people a lot of time to understand what all the fuss is about.

Co-op was one of four new wrinkles Google unveiled at Google Press Day 2006. It was also the only one that drew a lot of "what the hey" shrugs in reaction.

What Google seems to have going here is a way to add a new layer of results to searches at Google.com. The new parsing comes from Google Co-Op, where one finds a collection of Web sites that co-op members bring to Google's attention.

Some are from commercial interests, like movie, ticket-finding Web site Fandango.

It's done via 'tagging', or, as Google calls it, labels. Tagging is a way of noting a Web address for a large number of others to pick up.

There's a lot more to the Co-op facet, that much is assured. But so far some people are a little lost. And that seems to include the folks over at the venerable Searchenginewatch.

In a review of Co-op, Searchenginewatch editor Danny Sullivan wrote of some of co-op's features not working. "Let's pretend they work," he wrote. But when describing another step further into the process, Sullivan threw up his hands in frustration. "I'm lost," he wrote.

He concluded, though,  that "this is Google making a giant and somewhat perplexing leap into mass tagging."