You can try this in your controller :
graph = Koala::Facebook::API.new(session[:token])
user = graph.get_object("me")
@friends = graph.get_connections(user["id"], "friends?fields=id,name,link")
session[:token] : contain my token
and in your view for example :
<% @friends.each do |f| %>
<%= link_to f["name"], f["link"], :target => '_blank'%>