The unavoidable result of having a monumental number of services for doing exactly the same thing in the very same way is that people end up joining one or the other more or less at random. And after they have joined one, they decide to give the other a try.
At the end of the day, the person has five different usernames and no clear idea about what service has got a true edge over the other.
That is what has happened to location-based networks. I bet we won’t find a single user that is not part of Foursquare and Gowalla at the same time. That can turn the whole experience into something quite chaotic, and it was only a matter of time before services like Check.In were to emerge. We can define it very simply: it is a unified way for checking in. That is, if you are on a venue you simple launch the app and you will be capable to check-in to the very same place across different networks at once.
So far, supported services include Foursquare and Gowalla along with Brightkite (they are the ones behind the app, actually). Other services like TriOut and Whrrl have also begun being supported since the site left private beta – right now, it can be used by anybody. If you want to sample it in action, just pay the mobile site a visit using your phone or iPad and start checking in and out at will.
Check.in In Their Own Words
“One checkin to rule them all.”
Why Check.in It Might Be A Killer
It simplifies the way in which people approach location-based networks at a time in which everything was becoming a little muddled.
Some Questions About Check.in
How far can this eventually go? Are companies really willing to share the data that they have collected? 
