##A little tool for calculating and previewing ideal line lengths
A live copy is up on http://snipergirl.com/linelength
The ideal line length for typography is said to be somewhere between 50 and 75 characters per line. This tool allows you to calculate and preview ideal text width with different characters per line, fonts, letter spacing and font sizes
This one is really simple. Just put the files wherever you want them and it should work. It uses simple CSS and JQuery.
The "range"/slider inputs should degrade on browsers that don't support them to text inputs and still work.
Included under 'tester' is a small web app that uses JQuery to calculate ideal line lengths. A live copy is up on http://snipergirl.com/fonttester