auto resize text (font size) when resizing window?

Try a jQuery plugin like FitText. It automatically sizes text to fit the width of the parent element.

Another jQuery plugin with the same goal is BigText (demo).

I've had to do this myself. What I did was that I set a base text size for the body, and percentages for all other sizes. I then used a simple jQuery script to change the base size on window resize. The other sizes then update as well.

I used something like this:

$(function() {
    $(window).bind('resize', function()
    {
        resizeMe();
        }).trigger('resize');
    });

and in the resizeMe-function, I had this:

//Standard height, for which the body font size is correct
var preferredHeight = 768;
//Base font size for the page
var fontsize = 18;

var displayHeight = $(window).height();
var percentage = displayHeight / preferredHeight;
var newFontSize = Math.floor(fontsize * percentage) - 1;
$("body").css("font-size", newFontSize);