One of the fundamental principles of GTD is that you should be able to quickly look at your list of to-dos and easily see what your next items are and what you're currently working on, all wrapped up in a service that makes it easy to enter your ideas and to-dos. Pegby is a new web app that's designed with that goal in mind.
Web-based to-do tools are a dime a dozen, and every week a new one appears. What makes Pegby a little different is that it combines some of the great features of a tool like Trello with a focus on narrowing your view, so you focus only on the things you're working on now, the things you'll work on next, and the things you've completed, right in line with the GTD philosophy. The service gives you a view with three columns, each corresponding to one of those types of to-dos, and adding tasks is as simple as clicking in one of the columns to start a new "card". You can drag any card from one column to another and create new boards for different types of to-dos like "personal", "work", "family" and so on.
Once you've added a few to-dos (in the form of cards), you can tag them to keep them organised, colour-code them, and if you ever want to add more tasks, you can even email them to a special address Pegby creates for each of your boards. Pegby is completely free, but if you love the service, the service can suggest a donation amount that will help keep it running. The service is in invite-only public beta, but when I signed up it only took a matter of moments for my invite to arrive. If you've tried Trello and wish you could find a service that feels a little faster and more focused, Pegby is worth a look.