Finally, BlackBerry users can easily keep up with their friends on Foursquare with an app. Though the popular social site has both iPhone and Android applications, a BlackBerry app was conspicuously absent. If you're not familiar, Foursquare is a social application that allows you to "check in" to public places — bars, restaurants, bus stops, wherever — and also view where your friends have checked in. You earn badges for a certain number of check-ins, or for checking into certain types of places (I was far too excited to receive the "Don't Stop Believin'" badge for my presence in a number of karaoke venues). They announced recently that they'd moved from a city-only model to supporting Foursquare everywhere, meaning any venue anywhere is fair game for check-ins.
I have a few BlackBerry-toting friends who will be excited they no longer have to use the web browser on their BBs to access Foursquare. Installation instructions and answers to FAQs are posted on the Foursquare site.