Quote: "I'd like the user to be able to press this button to share their high score with their facebook buddies"
Facebook have changed the permissions since I last looked at this and I think an app requires a special permission to post without the user needing to do anything, and I don't think people liked apps doing this. AppGameKit pops up a Facebook dialog asking the user to double check the content and click the share button to confirm, which should still be ok but I haven't tested it in a while.
Be careful when including links in posts as I remember something about Facebook locking it down to only links to your own website, as specified in your Facebook app settings, but I may be wrong.
Quote: "what goes in "Default Activity Class Name"?"
Your package name followed by ".NativeActivity", for example if your package name is "com.mycompany.myapp" then it would be "com.mycompany.myapp.NativeActivity"
Quote: "Should I use the fb commands, or simply go for the OpenBrowser method ?"
Both should work, although the built in commands might be easier for the user since the sharing process is contained within the app, and login may not be necessary if they have the Facebook app installed.
