I gave a presentation last night on Facebook Integration using the Facebook Developer's Toolkit (FDT). FDT is available on CodePlex and effective with FDT release 3.0 has been renamed to the Microsoft Facebook SDK. Click HERE to download my Power Point presentation and sample C# projects from last night's event.
Facebook offers several ways to implement Facebook applications. When integrated within the context of the Facebook web site, such applications are referred to as Facebook Canvas applications. Canvas application take on two major flavors; IFrame constructed applications and Facebook Markup Language (FBML) applications. External web sites can also enable Facebook users to use their Facebook login IDs within respective external web sites, referred to as the Facebook Connect feature. Windows desktop applications can also be written to benefit from Facebook and gain access to Facebook data, either as Windows Winforms or WPF applications.
The Microsoft Facebook SDK wraps the Facebook REST API to simplify and facilitate ease of development of each of the above application/ deployment types.
Download the Power Point and code from the 1st paragraph to learn more.