I use it to enter goals, assign a weight to each goal, and then track each day I've done a goal. Goals can either be positive or negative points, and there's a 30, 60, and 90 day graph to see how well you do. Simple, easy, and surprisingly motivating for me; I enjoy seeing how high I can send the graph each day.
I try to stick to a small number of resolutions each year so that I'll actually implement them. So I currently have 3 resolutions, weighted at 2 points each. My resolutions are:
'Nuff said. I want to run the Olympia marathon in May, and to get there, I need to do this.
This one is hard to explain, but involves doing instead of asking permission, confronting situations (or people) when I'm upset but typically have stayed quiet to preserve harmony, and becoming more comfortable with making decisions on limited information. In general, it's about risking the status quo to do something I feel strongly about. (This sometimes leads to amusing conversations in my head, where I try to decide whether something I did qualifies as a risk and thus deserves a check mark. Often after I've done something, it seems far less risky than it did when I was considering it.)
Since I moved, I have friends and acquaintances scattered everywhere now; I want to keep those up.
I also have three goals that are probably more properly habits I want to acquire. These are only weighted as a single point and are Inbox at zero (my inbox filling up is generally a sign that I've let my processing system lapse and am not being particularly productive at work), Do something crafty (I often forget how much I enjoy crafting), and Do something you've been avoiding (usually a small task that makes me happy to have complete, but is just annoying enough to do that I've ignored it for a while).
Several of my goals have been influenced by The Happiness Project, a blog about what it means to be happy. It's a fascinating read, and far less sappy than the title indicates.