Howtoforge posted a guide about installing Linux without burning an ISO to CD/DVD

I am describing here a method to install Linux without using a DVD ROM or CD Drive; I have checked it myself.
There are many ways to do so you can install Linux by
1) booting from the network;
2) having an ISO image on your hard disk;
3) booting from USB;
4) installing a linux system from scratch by building your own.

  Install Linux Without Burning An ISO To CD/DVD - Use The ISO Downloaded To Your Hard Drive