A couple of months ago I had the pleasure of meeting Di-Ann Eisnor, one of the founders of Platial. As a result, I got an invitation to their preview site, so of course I poked arond and checked it out. I don't think I fully understood it at first, but after playing with it a little, I think it's a very cool idea. Platial is a collaborative atlas. The atlas is built by users submitting places, and tagging those places with multiple tags. For instance, I tagged Churchill Downs with Louisville, horses, gambling, derby, etc.
So what can you do with it? Well for one, if you are going on vacation, you can see what cool places people have tagged that you should visit. You can also search for the intersection of tags. Maybe I want a kid-friendly mid-priced italian restaurant on the east side of Louisville. I may be able to find those things by searching tags. Ultimately, it's a way to define an atlas that has information users find important, instead of just phone numbers and addresses. So if you are into this kind of thing, check out the site, and tag some of your favorite places in your own town.