The syncro is a small script that I use on my Alix board with an Ubuntu installation. The script uses aufs for mounting part of the file system into a ram disc and write back the changes on shutdown. This is used mostly if you use a flash disc as your root partition. Since the log files would write quite often to your disc and you like to reduce this as much as possible for flash discs, since the write cycles are limited. This way you only have this once at shutdown.
I got the idea of using aufs from Voyage Linux. The script is mostly copied from there I only added the possibility to set the directories within a config file and removed some addition where they remount the file system as writable.
This script expects that you have aufs installed and working. You need to compile aufs for your specific kernel since it needs to load a kernel module.
To install just copy the main script syncro into /etc/init.d/ The config (syncro.conf) file you need to copy into /etc/.
To configure the directories to mount into the ram disc see the config file.