I used to be a fan of the has_finder gem written by Nick Kallen.
Now with Rails 2.1, this functionnality is built-in so you don’t need to install the gem.
The named_scope method allows you to add finders to any model. A code snippet is worth 10000 words :

class Story < ActiveRecord::Base

  named_scope :hilarious, :conditions => ["type [...]

It’s been a while since the last edition of Rubyize this. I have waited all this time because I like when people become impatient. I have received 254 939 emails from desperate people asking me : “When will you post your 5th edition?”, “Is it hard to be that excellent?”, “You rock Frank. Warm kisses… [...]

The 3rd edition marked the beginning of a new association between Rubyize this and RefactorMyCode. I did things in a rather clumsy manner, telling people about how cool RmC was while asking them to use pastie to submit their refactored version of the code. At that time I didn’t realize that RmC and Rubyize this [...]