Heyevent was at one point the world's most popular event recommendation service with 600k+ registered users. We fetched events from Facebook and sent out weekly personal recommendations for upcoming events. The recommendations were based on the events that the user had previously attended.
Unfortunately, due to newly imposed limitations of the Facebook API, as well as expensive hosting costs and dwindling traffic, we've had to close down Heyevent and move on to new projects. Below are links to some other projects.