Interesting contest Nog! I just might try it out.. heck, if I can make my site roughly 60k in size (homepage), I'm sure I can reduce the weight by 6 times..
I checked ouy your sample book site. Very nice!
Just two notes off the top of my head that I can think of..
As far as images are concerned, have you heard of smush-it.com? (without the dash though... funny, when I previewed this post, the s h i t aspect got asterisked) It is a tool (I believe written by someone over at Yahoo) that does exceptional under the hood image optimizations which don't effect visual quality, but reduces image overhead (to which degree depends on many variables I'm sure).
So I examined your book site through smu**** and found you can squeeze an additional 96 bytes!!!! OK.. over the top, I know.. but you get the idea.. a great tool if you want to maximize the most out of image optimization.
I also checked you site through Yahoo's Yslow plugin for Firefox, and noticed that your source code isn't gzipped. Not sure if your server supports it or not.. but something to check into.. might be able to shave some more off there.
Overall, at 5 http requests and 9.2k, very nicely done!!
Very interesting concept.. I really should give it a whirl 🙂