Rails - Aug 2006 - pimp my code?? Using self.new in class methods, brittle design & testing such methods

It''s way past midnight and I''m about to go to sleep. 
I''m having
doubts about my code now that I''m trying to test as I go.

Now my model follows the pattern of the LineItem model in the rails book.

Basically the User has one Group and this one Group has many Friends
(polymorphic two-way as "befriender" and
"befriended"--users).

from Friend.rb (here the "befriender" and "befriended" that
are passed
into the model are User objects)

def self.befriend_user(befriender, befriended)
  unless befriender.is_friends_with(befriended)
    friend = self.new
    friend.befriender = befriender
    friend.befriended = befriended
    befriender.group.friends << friend
    friend
  else
    return
  end
end


Should I be breaking this up into smaller methods?  Is there a better
way to do it?  Is my design brittle or convoluted?

How would I write a Unit Test for the above?

Really stupid questions: why do I need the "friend" right before the
else?

I know these are a lot of questions but I really can''t find any good
information out there about good design patterns for an integrated
rails MVC/TDD approach so a few pointers would be appreciated.


Cheers,

Sam