Porteus

Have ever thought about making a version that can be install on a Hard Drive? This is just a thought. If I knew how I would like to try.

The same way as on pendrive. You don't need to install - add entry for porteus in your bootloader configurable file - many examples on forum.

This is a newcomer's post about installing on hdd:
http://forum.porteus.org/viewtopic.php?f=125&t=4605

Here is a related post about hdd installations:
http://forum.porteus.org/viewtopic.php?f=48&t=4471

Thank you for leaving space for me to add more info sources.
FAQ (answer to question): http://www.porteus.org/faq/desktop-faq.html#four
Tutorial (how to install): http://www.porteus.org/component/conten ... rd%20Drive