First of all, thanks for your fast reply 
Currently Im using a profile and friendship model with a modified
version of acts_as_network(in the end of the reply). This is really bad
code, and the query they provide to me when I want friends is not
exactly what I want.
This queries 2 times the friendship table: first looks for all the
profile_id column and then another query looks for friend_id column, and
in this way is hard to sort, limit and offset data.
I would like to make a single sql request that looks for in the
friend_id OR profile_id for that id. In this way it’s easy to offset,
limit and sort my data.
So… this is the code I’m talking about 
Profile model:
has_many :friendships
acts_as_network :friends,
:through => :friendships,
:foreign_key => ‘profile_id’,
:association_foreign_key => ‘friend_id’,
:conditions => {‘friendships.accepted’ => true}
acts_as_network :friends_pending,
:through => :friendships,
:foreign_key => ‘profile_id’,
:association_foreign_key => ‘friend_id’,
:conditions => {‘friendships.accepted’ => false}
Frienship model:
belongs_to :profile
belongs_to :profile_target,
:class_name => ‘Profile’,
:foreign_key => ‘friend_id’
Acts as network modified:
def acts_as_network(relationship, options = {})
configuration = {
:foreign_key => name.foreign_key,
:association_foreign_key => “#{name.foreign_key}target",
:join_table => "#{name.tableize}#{name.tableize}”,
:order => ‘friendships.updated_at’,
:limit => 1,
:offset => 2
}
configuration.update(options) if options.is_a?(Hash)
if configuration[:through].nil?
has_and_belongs_to_many "#{relationship}_out".to_sym,
:class_name => name,
:foreign_key => configuration[:foreign_key],
:association_foreign_key => configuration[:association_foreign_key],
:join_table => configuration[:join_table], :conditions =>
configuration[:conditions]
has_and_belongs_to_many "#{relationship}_in".to_sym,
:class_name => name,
:foreign_key => configuration[:association_foreign_key],
:association_foreign_key => configuration[:foreign_key],
:join_table => configuration[:join_table], :conditions =>
configuration[:conditions]
else
through_class = configuration[:through].to_s.classify
through_sym = configuration[:through]
# a node has many outbound realationships
has_many "#{through_sym}_out".to_sym, :class_name =>
through_class,
:foreign_key => configuration[:foreign_key],
:order => configuration[:order]
has_many "#{relationship}_out".to_sym, :through =>
“#{through_sym}_out”.to_sym,
:source => “#{name.downcase}_target”, :foreign_key =>
configuration[:foreign_key],
:conditions => configuration[:conditions],
:order => configuration[:order],
:select => ‘profiles.*, friendships.updated_at AS
friendship_updated_at, friendships.profile_id, friendships.friend_id,
friendships.accepted AS friendship_accepted, friendships.rejected AS
friendship_rejected’
# a node has many inbound relationships
has_many "#{through_sym}_in".to_sym, :class_name =>
through_class,
:foreign_key => configuration[:association_foreign_key],
:order => configuration[:order]
has_many "#{relationship}_in".to_sym, :through =>
“#{through_sym}_in”.to_sym,
:source => name.downcase, :foreign_key =>
configuration[:association_foreign_key],
:conditions => configuration[:conditions],
:order => configuration[:order],
:select => ‘profiles.*, friendships.updated_at AS
friendship_updated_at, friendships.profile_id, friendships.friend_id,
friendships.accepted AS friendship_accepted, friendships.rejected AS
friendship_rejected’
# when using a join model, define a method providing a
unioned view of all the join
# records. i.e. if People acts_as_network :contacts :through
=> :invites, this method
# is defined as def invites
class_eval <<-EOV
def #{through_sym}
UnionCollection.new(self.#{through_sym}_in,
self.#{through_sym}_out)
end
EOV
end
# define the accessor method for the reciprocal network
relationship view itself.
# i.e. if People acts_as_network :contacts, this method is
defind as def contacts
class_eval <<-EOV
def #{relationship}
UnionCollection.new(self.#{relationship}_in,
self.#{relationship}_out)
end
EOV
end
