The block of text below - which is in a DIV with a width of 400 pixels - will have its font resized until the block hits 256 pixels in height. The code increases the font by 1 pixel until it hits the target, then rewinds by .1 of a pixel until it gets just under the target. On Firefox 3.0/FC10 it doesn't actually seem to recalculate properly on these smaller increments, so this fine tuning is a bit wasted - not tested on other browsers as yet...