Is the fb_graph gem better?
It seems to be newer, but the facebooker has a lot more people using.
http://github.com/nsanta/fbgraph
http://github.com/mmangino/facebooker
Update:
I looked into koala, and it seems it is a good choice as well.
http://github.com/arsduo/koala
I also figure out that fb_graph is different than fbgraph. This is the right one:
http://github.com/nov/fb_graph
And there is a new facebooker, that uses that Open Graph API, but it doesnt look as mature as the others: