Up until now I just put all my jQuery goodness inside the $(document).ready() function, including simple functions used in certain user interactions.

But functions that don´t require the DOM document to be loaded or are only called afterwards anyway, can be placed outside the $(document).ready() as well. Consider for example a very simple validation function such as:

function hexvalidate(color) {
// Validates 3-digit or 6-digit hex color codes 
 var reg = /^(#)?([0-9a-fA-F]{3})([0-9a-fA-F]{3})?$/;
 return reg.test(color);
}

The function is only called from within the $(document).ready() function though.

What is best practice (syntax, speed); placing such a function inside or outside the jquery document ready function?