Planely is a very novel social application. It basically lets you learn about people who will be in the same plane that you are taking, get in touch with them, break the ice and arrange to sit together. This can be done both for professional and for personal purposes. But my money is firmly on the personal side of the service…
Still, the potential this has got when it comes to professional collaboration should never be overlooked. Just think of all the time that can be saved by working things out while you are airborne.
Using Planely is a mere matter of signing up for a (free) account and then entering the number of the flight you are going to be in. Planely will show you both who is going to be in that plane and in the airport. Having that information, the Social Web will let you do the rest and know if there is any person there that you would like to get to know better. You will be able to contact him/her well ahead of the plane flight, and start interacting straightaway.
Planely.com In Their Own Words
We hope to change the airline industry for the better by connecting you with the greatest untapped resource of knowledge and entertainment on your journey – your fellow fliers.
Why Planely.com It Might Be A Killer
Plane flights together often end up creating solid bonds. This site makes meeting up with the right one that much easier.
Some Questions About Planely.com
What measures have been taken to ensure this is safe for everybody? 
