Utility Belt

Utility Belt is a grab-bag of tricks, tools, techniques, trifles, and toys for IRB, including convenience methods, language patches, and useful extensions. It also includes a couple command-line widgets. Its primary inspirations were an awesome gem called Wirble and a blog post by Amy Hoy called "Secrets Of The Rails Console Ninjas".

FEATURES

• Interactively edit IRB code in your preferred text editor
• Read from and write to OS X clipboard
• Post your code to Pastie with one command (OS X only)
• Kick-ass Unix-style history buffer
• Write command history to file or vi
• Grep classes and methods for strings
• Verbosity controls for regular IRB and Rails console
• Finder shortcuts for Rails console
• Upload shortcut for Amazon S3
• Command-line Amazon S3 upload script
• Command-line Google shortcut (OS X only)
• Auto-indentation
• _ special variable (like Unix shell var !!)
• Extremely basic themes for Wirble syntax coloring
• Pascal/JavaScript-style "with" statement
• String#to_proc
• Grammatically-correct is_an? method - no more "is_a? Array" statements
• One-character exit command

http://utilitybelt.rubyforge.org/
http://www.rubyinside.com/irb-lets-bone-up-on-the-interactive-ruby-shell-1771.html
http://rors.org/2009/12/20/10-rails-console-tricks.html