As promised, I have published a more AJAXy example of the classic Tinderbox waterfall, built using the new Tinderbox JSON output mode:
This version uses gzip encoding for the JSON data, only reloads the page when new data is available, and I've cleaned up the code quite a bit (split into separate functions for easier profiling, using innerHTML instead of document.write(), etc.).
I'm hoping to use this as a base to start making more fundamental improvements to the waterfall UI. Jesse suggests having the column headers always at the top as you scroll, which sounds pretty awesome to me. luser's test page now shows the percentage change from the last run for performance numbers, which I will merge into my version soon.