Lazybase: Quick and easy web-based databases
Lazybase is a web-based database app that fits the "simplest thing that could possibly work" paradigm. It's not flashy (or even AJAXy), but it's clean, easy to use, and it just works. It's a registrationless service, so to create a new database you just give it a name and enter your e-mail address. When you create a database you're given two URLs, one that lets people edit the database and another that's just for viewing. Though simple, Lazybase has a few nice advanced features like graphs and maps, relationships (like books to authors), import from Excel, RSS feeds, and bookmarklets. It also has a feature that lets you embed a live database view into any web site. If you're looking for an easy, free way to keep structured data online, Lazybase is worth a look, though I'm in agreement with Andy Baio that it's desperately in need of an open API.