I've test SliTaz Cooking 20080716 today and found out their work is quite nice. :-)
So I take a look at SliTaz's kernel module selections from /proc/config.gz, and compile the corresponding modules with ubuntu 2.6.24-19-generic, the result is 12M compare to 23M of the original /lib/modules, after mksquashfs, there's a 11MB difference.
Then I tried Midori, a lightweight Webkit/Gtk+ browser (takes about 23MB using apt-get). Here's what it looks like in plate UI:
Looks weird but still usable. :-)