Added role helper methods, and set some abilities

app/models/user.rb

@@ -1,6 +1,8 @@
 class User < ActiveRecord::Base
   include Gravtastic
 
+  before_create :set_default_role
+
   belongs_to :role
 
   gravtastic :size => 165, :filetype => :png, :rating => 'R'
@@ -18,7 +20,24 @@ class User < ActiveRecord::Base
   has_many :topics, :dependent => :destroy
   has_many :posts, :dependent => :destroy
   
+  def registered?
+    self.role == Role.find_by_name('registered')
+  end
+
+  def banned?
+    self.role == Role.find_by_name('banned')
+  end
+
+  def moderator?
+    self.role == Role.find_by_name('moderator')
+  end
+  
   def admin?
-    self.is_admin
+    self.role == Role.find_by_name('admin')
+  end 
+  
+  private
+  def set_default_role
+    self.role ||= Role.find_by_name('registered')
   end
 end