I've registered on Foursquare - shock horror - have no idea why - got bored and was playing with it!
It reminds me of clocking on at the mill - yes I did work in a mill in a previous life - when we still had some in the UK that is!
However, I now have powers - I am the Mayor of the Travelodge Milton Keynes Central - wow! I can see how these badges become addictive. I'm going to try and become the mayor of my local ASDA next. Seeing as I seem to meet most of my work colleagues there doing the weekly Saturday shopping this could end up as a cross company Badge competition!
Its all a bit scary - you can see what others have been up to and others can see what you have been up to - useful for filling out your timesheet! Though I have discovered that connecting up with a work colleague that I wouldn't normally have much to do with has created an odd relationship. I know how he gets to work what he does for lunch and when he arrives home for the weekend. Is this a good thing - not entirely sure. There is something there, but it feels a little voyeuristic to be honest.
I can see that 'checking in' you could also meet up with new contacts - useful on a work front as well as social. I now feel obliged to check in at my mayoral residence(s) and I do feel sense of responsibility to these places weirdly!
Obviously something that needs a bit more investigation.....