On Wednesday evening Facebook launched Facebook Places, an event of some significance. I spent some time over the weekend trying to pull together all the best information into one place, which I share below. I'll also be regularly updating this post as things develop, so be sure to bookmark this post and check back often.

This video from Facebook is a good place to start getting your head around how it works from a users perspective (especially if you're outside of the US, the only country with access to the service currently), as is Walter Mossberg's early review. Inside Facebook have a good guided tour of the features and privacy settings and also bring news of how friends' check-ins appear on your events page. However, Kunur Patel describes her friends' initial reactions to being checked in by her when they were out for dinner, which implies the product is going to take some getting used to (update: All Facebook draws attention to a brewing Facebook Places backlash).

The Wall Street Journal points out how this opens up competition between Facebook and Google, specifically the Google Places product aimed at local businesses and Nick O'Neill paints a grim picture of what this means for Foursquare while Techcrunch tries to decipher what Foursquare themselves think.

What Marketers need to know
Inside Facebook has a great hands-on guide to how marketers and businesses can start using Facebook Places and Facebook themselves have put together a FAQ on Places for Advertisers. Michael Lazerow looks at what opportunities Places opens up in terms of app development, Debra Aho Williamson has done some thinking about the long term implications for marketers, Josh Constine looks at its potential to change how people find and use real-time information and Tom Cummings puts it all in context. However, in the short term, it looks like the introduction of Places has slowed natural Facebook page fan growth by over 50%.

Update: Inside Facebook have a great guide to Facebook Places developments over the past few weeks and both Context Optional and Fan Appz have released Places based apps for brands allowing them to run promotions and mimic Foursquare's game mechanics.