Simple "Send Email from Ruby" method - Using Net::SMTP to talk to the local SMTP daemon directly to send mail. Not elegant, but a useful quick hack.

Helper to Display Rails Flashes - A helper method that formalizes and simplifies the displaying of certain flash variables in Rails views.

Rails and Vim - A script to open an entire Rails project in Vim (searches through for models, controllers, etc).

Using Ruby hashes as keyword arguments, with easy defaults - Make your life (and methods!) simpler by merging in a set of default options with the supplied ones.

Ruby daemon library - A useful Daemon module to simplify the creation of daemons in Ruby (the daemons gem may be better for this in the long run though).

Wrap Text with a Regular Expression - Wraps text to a specified column width using a single gsub.

Test Driven LDAP with Ruby - Testing the LDAP client library for Ruby (and your LDAP server!)

Ordinals for all Numeric Types - Extending Ruby's numeric types to suffix "st", "rd", "th", etc.