Yelly likes to yell. To make the magic happen for simple cases just invoke him ala:
bundle exec rspec --require=yelly_the_yellingist_formatter.rb --format=YellyTheYellingistFormatter spec/models/your_file_here_spec.rb
In closing, >:O
Updated to Rspec 3.0's formatter interface.
This fork edited to say the failure aloud, mainly so I don't have to be resizing Tmux panes to read failure messages when working on a smaller screen.