Not least because I had a similar great idea a couple of years back, except I didn’t think about how cool it would be on the web. We travel a lot where I work, and I thought a system which fed out of the travel booking system and let people know who was co-inciding would be great. I even put up a project submission, but it was declined. Good thing, because now we have even more incentive to use Dopplr!
I’m adding a feed of my Dopplr trips into the sidebar of the blog. If I happen to co-incide with you, wether I know you in person or not, let me know, I may just have time to catch up for a beer and say hi!