Basically, people list one or more current significant goals in their life, and blog about how they are doing towards achieving it. The site automatically links you to everybody else who has either set that goal, is currently working towards that goal, or has achieved that goal. Instant support group. The software allows you to cheer each other on (and keeps track of how many 'cheers' you've received) and to watch each other's struggles and successes etc. Having recently been greatly cheered by the discovery that everyone else in my Wednesday evening drumming class was struggling nearly as much as I, I can see how this could be a very useful site.
So I set up my own 43 Things page, and listed world drumming as my first goal. Read my entry on drumming here.
I like this site a lot. So now, do I dare list "writing great Canadian SF novel" or would that be premature, retirement still being 12 years away?