http://typing.io/ - 웹에서 개발 타이핑 연습하기. 

Practice typing the awkward characters in code.

* 메인화면 - 구글 계정으로 로그인하기

* 로그인 하면 각 개발언어와 예제 소스가 버튼모양으로 선택을 기다리고 있다.

* jQuery 선택해서 들어간 후 열심히 타이핑 하면 된다. 빨간 화살표가 나오면 빽스페이스( <- )로 삭제한다. 

  다 입력하면 멋들어진 결과가 나오니 열심히 오타없이 빨리 입력해보기 바란다.

CSS Sprite Sheets: Best Practices, Tools and Helpful Applications

http://webdesign.tutsplus.com/tutorials/htmlcss-tutorials/css-sprite-sheets-best-practices-tools-and-helpful-applications/

Using CSS sprites, instead of a collection of smaller individual images, will improve your web pages’ performance and keep things more organized. Let’s take a look at some best practices and some helpful tools for your sprite-making workflow.

The name sprite might remind you of gaming sprites; retro console games and even browser-based games these days:

Tools to Help

There is a massive range of tools to make your sprite sheet generation as easy as possible. When you create and design with a range of individual images, compile them all into one sprite sheet at the end – the ‘after’ method.

Here are some of the best Sprite Sheet generators:

• Compass
  Price: Free!
  Compass includes a brilliant sprite and stylesheet generator, building the sprites from your individual images stored in a folder. Also related is Sass; a CSS preprocessor that makes your CSS clearer, more organized and easier to maintain. More info: http://enva.to/z12V70
  http://compass-style.org/
• Lemonade
  Price: Free!
  Extremely simple and easy to use, Lemonade uses Sass as mentioned above. All you need to do is add a line of code to your Sass or SCSS Files and you’re done – a sprite is generated. However, the developers have now moved on to work on Compass and Sass – so don’t expect any updates to Lemonade anytime soon.
  http://www.hagenburger.net/BLOG/Lemonade-CSS-Sprites-for-Sass-Compass.html
• SpriteMe
  Price: Free!
  A fantastic bookmarklet-based sprite sheet generator and viewer. It can be used to view any sprites used on any website. The best feature is that you can design your website using individual images, then run SpriteMe. It will quickly generate a sprite sheet that you can export and also generates the associated CSS for the new sprite. It even injects the sprite into the current page. If you’re used to working with individual images, this offers the easiest transition to working with sprite sheets. I’ll go into more detail about how to use SpriteMe later on.
  http://spriteme.org/
• Fireworks CS6
  Price: Definitely not free!
  The latest version of Fireworks in Adobe’s Creative Suite includes Sprite Sheet generation.
  More info: http://enva.to/IURM73
  http://www.adobe.com/devnet/fireworks/articles/css-sprites.html