- Oldie, but goldie - Building responsive layouts with SASS, an extensive tutorial by Chris Eppstein, the creator of Compass and member of the SASS core team
http://chriseppstein.github.com/blog/2011/08/21/responsive-layouts-with-sass/ - Speaking of SASS and Compass, Envato has just released very helpful video introduction to the subject
http://webdesign.tutsplus.com/tutorials/htmlcss-tutorials/sass-and-compass-for-web-designers-introduction/ - Handy utility for parsing and normalizing email template html/css.
http://premailer.dialect.ca/ - Useful vim plugin for context-aware pasting
http://thechangelog.com/post/15655273063/vim-pasta-smarter-context-aware-indented-pasting-for-vim - With the Sinatra Gon gem, you can export easily variables to javascript
https://github.com/gazay/gon-sinatra
