Minify your JavaScript

Many people will be familiar with this technique. Essentially, you take your JavaScript, remove some characters, and then simplify the variables. As demonstrated below:

Initial (66 characters)

1. function Sum(number1, number2) {
2. return (number1 + number 2);
3. }

Characters removed (54 characters)

1. function Sum(number1,number2){return
2. number1+number2;}

Compacted (30 characters)

1. function Sum(a,b){return a+b;}

You're left with less JS to download, and there's a hidden benefit: runtime performance. With tighter code and smaller variable names, the runtime can look up variables faster, improving download as well as runtime performance.