I assume this patch is going to end up in 1.9.3 but in the mean time: How To Get That Edge Ruby Faster-Loading-Hotness in Ruby 1.9.2 Now

Very easy to do, even for someone fairly new to Ruby, like me. You'll end up having to change your .rvmrc file to rvm use ruby-1.9.2-p180-patched and do the necessary steps to populate the new gemset (gem install bundler ; bundle install).

My guard/rspec/spork/growl went from a 1-2 second delay to pretty much instantaneous when saving a spec or associated controller/model/helper. bundle exec rake cucumber also doesn't feel nearly as sluggish.