I've recently, along with a few friends, become addicted to foursquare. It's great fun and adds a bit of excitement to an otherwise boring trip to the shops. (Okay, I'm easily pleased).
But one of the shortcomings of foursquare, and an odd one given that it's entirely location based, is seeing where you've checked in. You can go to specific locations within foursquare and see those locations on the map, but there's no way to see at a glance everywhere you've been.
To the rescue comes 4mapper, which does exactly what foursquare doesn't.
You can allow 4mapper to access your foursquare data and it will then plot everywhere you've been on a Google Map. Your locations are shown by white dots. The larger the dot, the more times you've been there. Click on a dot and it'll tell you the number of times you've checked in to specific locations. You can also display check-ins from other users.
It's nice and simple and gets the job done until foursquare decide to integrate it.