Another problem even with all 3rd party packages optified (or relocated to /opt which I prefer as being less of an ugly hack) is the apt-system with it's indexes, caches, and database. It can easily eat up 30 MB or more of your root fs even though there's not much stuff installed. Heck, solely disabling the extras-devel repo freed 3 MB on my root fs because the index files were that big.