As part of the redesign of my blog, I have made available a JSON feed containing all the dates on which I have published. This JSON dataset is being used internally by my server to produce calendars, 'on this day in' lists and the such like. But the reason I am making it available is simple - I want you to build things with it! 
The feed contains two sets of data - firstly, a hierarchial list called 'multi' which has the years, months and days that I've published listed inside of it. Secondly, it contains a list called 'flat' which lists every day I've published in a flat order. Why both ways? Well, I found myself writing code to sort through this list over and over again and thought that it would be easier just to double the amount of data to reduce the number of cycles processing it. I haven't done any testing, but it should be a little bit quicker on my server to do it this way.
Why not XML? Well, I may do an XML version soon, but I'm lazy. With JSON, it's as simple as making a PHP array and pushing it through a json_encode().
So, what could you do with this? Well, it's up to you. Build me a widget or a funky, slidy Ajaxy calendar, visualise the data. Anything you want, really. Although I'm not totally inexperienced with JavaScript, I'm stil very much a beginner.
Remember - the date format is quite simple - tommorris.org/blog/year/month/date to get the HTML, or put .opml on the end to get OPML 2.0.
