Just when you thought you'd learned about all the things your iPhone can do for you, along comes a new one: It can help you track your happiness. Taking part also helps someone write a PhD, so it's a double plus.
The new app is actually some psychology research being performed by Matt Killingsworth at Harvard, and it's designed to tackle one of nature's most ephemeral and yet fascinating questions: What is it that makes people happy? The site's blurb sets out the mission of the project, it's a "new scientific research project that aims to use modern technology to help answer this age-old question. Using this site in conjunction with your iPhone, you can systematically track your happiness and find out what factors--for you personally--are associated with greater happiness."
Essentially you sign up for the program, and then give the software a slew of personal information to give the researches some meaty data to think about later--it's stuff like how satisfied with your life you are, how much money you make, whether you're married, how liberal your political leanings are. Then, at repeated periods throughout the day you'll be pinged by your iPhone either by email or by SMS, and prompted to answer a short one-minute survey. This one asks how happy you are, what you're doing (yes, "making love" is an option, though hopefully it's an activity you'd prioritize over doing some science) whether you exercised recently, whether you're alone, who you're talking to and what you're thinking about.
After 50 successful survey answers you'll get a Happiness Report from the system, which will apparently help you work out the factors that contribute most to your levels of happiness. Or, I suppose, there's the flipside conclusion: You can learn what things make you most unhappy.
Hmm...that's where this idea gets interesting. I suspect most people who'd be generous enough to take part in the study are pretty self-aware, and already know, to a certain extent, what makes them happy. I just completed the first survey, and was told I was 60% happy--which doesn't actually tally as I'm very happy indeed. And surely having the iPhone as the chief input device will bias the survey? I understand it's a Web-connected gizmo you tend to have nearby at all times, making it ideal for the time-related part of the study...but Apple users tend to report high levels of satisfaction  with their products, and using the iPhone is a constant reminder of how cool it is. That's going to skew things a bit.