Why? If you're setting up your website right, you should be serving 1 HTML file + 1 JS file + 1 CSS file + 1 image for each request, and the latter 3 should all be cached indefinitely. (At least for static chrome - if you've got thumbnails, videos, or flash games you can't exactly sprite those.) His test file was 146K, which seems on the high side for HTML only, but I'd imagine serving 1 small file is faster than serving 1 large file.

1 image for each request? Are you putting all the images for each page into one image file, then cropping the needed region for each image on your page?

That's the idea: http://www.alistapart.com/articles/sprites/

Have you actually made any measurements?

Smaller pages are actually faster (both individually and collectively), though gzip is already fast enough that the difference is irrelevant.