Here are just a few things that I still remember:
* HISTSIZE and HISTFILESIZE in bash
* customizing your bash prompt to include rvm version $(~/.rvm/bin/rvm-prompt)
*
http://github.com/jtrupiano/johns-toolbox* running Chromium from the command line: nohup
/Applications/Chromium.app/Contents/MacOS/Chromium
--enable-extension-timeline-api > /dev/null
*
http://github.com/defunkt/gist* irb goodies: looksee/shortcuts and utility_belt
* homebrew for mac os package management
* keyboard shortcuts
* Evernote - wow