I just finished installing OS X on my Dell Mini 9 pic (as an aside – probably one of the best form factors I have owned for a traveling laptop). The instructions here:
are pretty good. I followed Section 2 Part A. One thing to note, when booting the system via the “small” USB drive you will have to press “esc” and select the larger USB drive to boot from. The syslinux/isolinux on the small USB drive will continue to boot in a loop until you break the cycle. Other than that everything worked like a charm right from the start (camera, audio, wifi, etc…).
I still need to install and tweet some additional settings and my 16 GB USB drive will always be close by (6 GB installation). Additional links and information are below – enjoy.