Nokia S40 users can now check in with foursquare, as the location-based mobile app is now available in a version that is compatible with the mobile operating system. From the foursquare Blog:

Our goal is to give everyone access to foursquare. But when we look at the world cell-phone population, we’ve often been frustrated by the fact that we don’t yet have a version to offer to the hundreds of millions of people who have phones running Nokia’s popular S40 operating system. The wise people at Nokia Beta Labs saw that opportunity, too, and decided to build one using our API.

It’s a full-featured foursquare, with all the core functionality, including check-ins, shouts, venue discovery, and friend info. And they’ve promised to keep developing this, with “more to come.” So, if you have a S40 (it’s been tested on the Nokia 5310, 6600 fold, 7230, C3-00, C3-01, and X3-02, but should work on all S40 devices), download the beta now. And Nokia is looking for feedback, so test it out and let them know what you think!