variable conditions in find queries

What is the correct syntax for using variables in find conditions?

I tried this but it doesnt seem to work, I also couldnt find any
documentation online

@vote = Vote.find(:all, :conditions => 'user_id = "@user.id"', :order
=> "created_at DESC", :limit => "5" )

@vote = Vote.find(:all,
                           :conditions => ["user_id = ? ", @user.id],
                           :order => "created_at DESC",
                           :limit => 5)

If you want to put more conditions:
:conditions => ["user_id = ? and group_id = ? ", @user.id, @group.id]

ActiveRecord quotes(..security...) the condition for you

claudio