Localley is a tool that broadens the functionality of Facebook Places by letting you check-in to places using a date and time in the future. It also allows you to view your check-in history on a Google Map, visualise your friends' latest check-ins and view the people who are checked in around you.
Localley's future check-in service lets you share your plans with your Facebook friends and even invite them to join you. For example, you can tell your friends where you will be tonight and when.
Localley really does seem to add some great extra functionality to Facebook Places. The site is currently in Beta. Hopefully some detailed instructions of use will be added to the site before a full launch. At the moment it is quite hard to work out some of the site's functionality.