If you're looking for another social network to explore, Flickr and Hunch co-founder Caterina Fake announced that her new project, Pinwheel, is now in a private beta. Pinwheel is a way to leave digital notes all over the world. They can be a snippet of text — a tip, a joke, a memory, a fact — or an attached photo left for others to explore and discover on a map. Users have the ability to make notes public or share something privately with one person in particular. To us, this sounds a lot like Color or Path, but Fake explained on her blog that what sets Pinwheel apart is the open-ended nature of notes, adding that people are already using the service to track their ancestry and record found objects. To make money, Pinwheel will allow businesses to create sponsored notes that direct customers to stores or promote products in unique places. The beta is currently available on the web and mobile web, with an iOS app forthcoming. If you want to search out some notes for yourself, you can sign up for early access.