Aquí les dejo unas Chuletas o Cheat-Sheets para todos los lenguajes de programación:

Expresiones Regulares (Regex)

• regex-cheatsheet-v1.png
• regex-cheatsheet-v2.png

Python

• python-cheat-sheet-v1.png

HTML/HTML5

• html-cheatsheet.png
• html-character-entities-cheatsheet.png
• html5-cheatsheet.png
• html5-canvas-cheatsheet.png

SQL/MySQL

• sqlserver-cheatsheet.png
• mysql-cheatsheet.png
• SQL Injection

CSS

• css-cheatsheet-v1.png
• css-cheatsheet-v2.png

Ruby on Rails

• rubyonrails-cheatsheet.png

Colores Web

• colors-cheatsheet.png

Javascript

• javascript-cheatsheet.png
• javascript-dom-cheatsheet.jpg

PHP

• php-cheatsheet.png

WordPress

• wordpress-cheatsheet.jpg
• wordpress-template-cheatsheet.pdf
  

jQuery

• jquery-1.7-cheatsheet.png
• jquery-1.3-cheatsheet.png
• jquery-1.2-cheatsheet.png
• Versiones jQuery
  

Node JS

• nodejs-cheatsheet.pdf

Angular JS

• angularjs-cheatsheet-v1.pdf
• angularjs-cheatsheet-v2.pdf

Prototype JS

• prototypejs-cheatsheet.png
  

TODOS LOS CHEAT SHEETS EN UN SOLO SITIO:

• Cheat Sheet : All Cheat Sheets in one page
• OverAPI.com | Collecting all the cheat sheets