Facebook “sharing” has always been about showing our friends how we want to be perceived. What we share gives others a look at what we like, what we think, and now, where we can be found.

Facebook Places, announced and released August 18 (at least for US users), is slowly rolling out to users of smartphones. After updating the Facebook app on my iPhone (twice – the first update included Places but without the check-in feature) I tested it out and it works. Nothing too exciting, or ground breaking… yet.

Facebook Places is not exploring new territory with the initial roll out. Other location tagging apps like Foursquare, Gowalla, and Yelp (to name a few) already offer check-ins, complete with badges, user tips, and proximity offers. But Places has what the others don’t – 500 million built-in users.

Interestingly enough, yesterday (the first full day of roll out for Places) Foursquare had a record number of new users. I image this spike was due to Facebook bringing attention to the platform through association – people had to test out the alternative. Unfortunately for Foursquare, I’m afraid those users will remain loyal to Facebook where they’ve already established themselves. Who needs another app to keep up with if you can have it all in one place?

Facebook Places has a lot of growth potential, but with it also comes the privacy complaints (again). Facebook has taken measures to address the obvious with the option to opt-out of all, if you so choose. By default you are only sharing your location with your “friends”. There are features where you can tag others when you check in, and there is a “Here Now” feature that allows everyone (even non-friends) to see who is at the same venue, but both can be turned off. So turn it off, or just don’t check-in… I’m not too concerned. On the other hand, I hope Facebook makes it easy to hide check-ins by over-sharers.

Ok, so what do I not like about it after day one?

1. Tag your friends is automatically enabled, and no notice is given to the person being tagged prior to it being posted. Not that big of a deal until your old college buddies decide to get you in trouble with the wife!

2. You can check in at any nearby location without actually being there. This is my biggest gripe about Foursquare – users can cheat and rack up points and badges, throwing a wrench into any legitimate promo offer by a business. (Related sidenote: An app that I have been excited about, Shopkick, goes the extra step and ties the check-in game directly into participating retail outlets, requiring you to actually go into the building to earn points – even product barcode scanning for added specials.)

3. A friend could come to my house and tag his/her location, ultimately letting everyone know where I live.

With that said, Places is a basic roll out with a lot of opportunities to be had by users and advertisers alike. Location has been the technology frontier in the social and mobile space, and Facebook is doing its part to unveil it to a very large audience. Looking beyond the “I Was Here” factor, I’m excited as both a user and a marketer to see how Facebook uses shared profile information and check-ins to provide relevant offers and suggestions. Where do you stand?