Fancy sharing your day-to-day life with someone you don't know, in return for a glimpse into their own world? Then 20 Day Stranger—an app which tracks your location and what you're doing, then anonymously shares it with one other person—could be for you.

Put together by the MIT Media Lab's Playful Systems group, it's an experiment in personal data sharing. The guys behind it explain their thinking:

It's a mobile experience that exchanges one person's experience of the world with another's, while preserving anonymity on both sides... For 20 days, you and a stranger will experience the world in your own way, together. You'll never know who it is or exactly where they are, but we hope it will reveal enough about someone to build your imagination of their life... and more broadly, the imagination of strangers everywhere.

Without doubt it's an interesting idea, though it's hard to work out which side of the fence it falls on: endearing, or just a little creepy? Also, it's likely that the experience of what it's like to use the app will vary drastically depending on who you're paired with—but, then, maybe that's where its charm lies.

If you find the idea oddly compelling, then you can sign up to participate in the experiment on the 20 Day Stranger website. [20 Day Stranger via Flowing Data]