http://www.magentocommerce.com/magento-connect/beetailer-facebook-integration.html

Beetailer. Your Online store on Facebook.

Beetailer integrates your Magento store with Facebook, Twitter and Google+, helping you to increase your sales and to reach more customers. It provides deep integration with Magento, including the shopping cart API, so customers can shop inside Facebook but they check out in your regular store. Beetailer is in use by thousands of ecommerce stores reaching over 50 Million fans.

This extension requires free registration on http://www.beetailer.com. Setup takes minutes and does not require any coding.

Features

Integrates with your existing store

No need to re-enter or migrate your product data. Beetailer will use your current catalog and stock information and keep it synchronized automatically.

It is easy to set up an event in Facebook.  It is even easier for someone to say they are coming.  They just click the RSVP yes link and presto they are registered for the event.  If you are doing a birthday party or some private personal event, that's fine.  But if you are doing a business event, you should not use Facebook events to capture RSVPs.

The main reason for this is that you do not get any data from facebook.  Services like Constant Contact, EventWax, EventBrite, Upcoming and the like allow you to capture names, email addresses and some other data if you wish.  Facebook has no means to get a list of email addresses from an event.  You could go to each person's profile and get their email address if they share it.  But that could take forever. 

The way to run a professional event is to use a service that lets you get the data for all the attendees.  This lets you easily pre-print name badges, send follow up emails, and do all sorts of other things with the data.  These services also let you print tickets.  You can require that the guests print these out and bring them to the event. This can ensure that only registered individuals are allowed in.

No doubt using one of these services is a bit more trouble for the user.  But it might be better.  A person who takes the time to do this is more likely to show up.

Social networks are about people and interacting.  What do you do if the people you want to interact with are on different networks or systems? There are more than a few social networks these days. Facebook, LinkedIn, Twitter are the tier 1 systems.  I would have to throw Yahoo and MySpace in there for good measure.  Then there are a host of secondary platforms like Orkut, Hi5, StatusNet(Identi.ca),  Plurk, Plaxo Pulse, Koornk, Miio.  Then there are intermediaries like FriendFeed, Ping.fm.  I could go on but I think you get the point.

Each of these platforms has some users.  Some have many and some have few.  How then does one interact with all of these platforms?  I'm sure that no one wants to directly interact with all of them all the time.  Imagine having to login to all those sites to post the same message.  And then having to monitor all of them for responses.  If the interaction is kept only within a platform, those on other platforms lose out.

The key then is platform interaction.  This means an API.  I use Tweetdeck.  And this allows me to interact with several platforms at once.  I go to one place and I see all the updates from Twitter, Facebook, and LinkedIn in one dashboard.  Ocassionally, I use HootSuite as well, which has similar features.  I never have to post anything directly to FaceBook.  My Tweets go there because FriendFeed reads my Twitter account and posts them there for me.  Talk about a time saver.  All this is possible because these platforms provide an API.  If Plurk did not have an API, I would never use it at all.  There just isn't enough to push me over the edge.