[CentOS] Centos on a Flash drive and Micro drive

I am considering putting together a 'micro server' that I can easily 
travel with.  I am seriously considering the decTOP, as at $99 (plus the 
cost of a 256MB SIMM) is amazingly priced.

But I want to run on batteries, so trash a real hard drive.  I have a 
couple of IDE to Compact flash adapters that support 2 flash cards.  So 
I was considering a 4Gb (or even 2Gb) cheap real fash card for the OS 
and a 4 or 8 Gb micro drive (I have a 4Gb sitting in a drawer gathering 
dust got to figure out how to fix its paritions that I messed up).

So I was thinking to put the more static parts of the OS on the flash 
card and the not static parts on the micro drive.

Obviously the Swap partition, /home, and /var/log go onto the micro 
drive.  What else?  /tmp?

Are /dev and /proc real things on disk or only pointers to the various 
devices?

And then how do I put all these directory trees on the micro drive.  I 
currently use a LVM partition for my /home on my notebook, but this is a 
lot more.  Do I do Symbolic links?  Or what.  Are there any howtos?  I 
have not found anything to help me so far.

Probably got at least a week to figure this out.  Obviously I don't have 
the system right now.  And monday it is off to San Fran for the IEEE 802 
meeting... (and the following week IETF in Chicago, family gets really 
upset when I have these 'back-to-back' conferences).