Dude,
There are a couple of ways to overcome this situation,
1. To have a separate /var partition defined (useful when your log files @ /var/log eat up your hdd and leave your machine unbootable)
2. As suggested by matthiar n crac, share your home directory with a special folder for www.
3. In my home I'm running a couple of test sites each mounted on an individual HDD (for large database testing and good I/O) and the document root appropriately set on apache httpd.conf.
The possibilities are countless in Linux:D
:)