I am putting the finishing touches to an article on the updates to the Force.com for Facebook toolkit I blogged about a few weeks ago. There are still some wrapper classes to finish off before releasing the code/toolkit, but I thought it might be handy to share some code snippets on you work with the toolkit. Overall, the process is very similar to the current toolkit: you register your application, and then start working with the Graph API via a series of wrapper classes. 

Here is a sample of a test method using the FacebookLike object. You will note that I am passing in an optional test stub to allow me to write test code coverage above the 75% threshold even though I have callouts. (there are some great articles on strategies for testing callouts in your code on developer.force.com if you are interested)