At first glance, keeping your diary on the internet may seem like a peculiar geek conceit, but it's actually a rather clever idea.
All you have to do is set up a diary (which is free and takes about 30 seconds) on the site, which you can then access from anywhere in the world.
So far, there's no real edge over a pocket diary. But - and here's the clever bit - you can chose to make your diary visible to anyone who knows its name and/or your password, so they know your availability and movements.
Even better, if you are doing business with someone who also has a virtual diary, you can suggest a meeting and the site will do the rest. It will calculate a convenient time, pencil it in and e-mail both of you asking if it's convenient.
And, although you can't have your virtual diary lovingly bound in hand-tooled leather, you can't leave it in the back of a taxi either.