Boot ISO Image From Your Hard Drive With Grml-rescueboot

With grml-rescueboot there is an easy way to boot an ISO image from your harddisk to test other linux distributions.

To install open a terminal and :
sudo apt-get install grml-rescueboot
or use software-center, synaptic....

Then move the ISO image ( e.g. elementaryos-stable-amd64.20130810.iso ) to /boot/grml/ :
sudo mv elementaryos-stable-amd64.20130810.iso /boot/grml

Update Grub 2 with the following command :
sudo update-grub
Sat Feb 08 14:10:11 ->sudo update-grub
Generating grub.cfg ...
Found linux image: /boot/vmlinuz-3.11.0-15-generic
Found initrd image: /boot/initrd.img-3.11.0-15-generic
Found memtest86+ image: /boot/memtest86+.bin
Found Windows 7 (loader) on /dev/sda2
Found Grml ISO image: /boot/grml/elementaryos-stable-amd64.20130810.iso
done


Reboot and you will see the new entry in your booting list.

Links :
http://ubuntuportal.com/2013/08/heres-an-easier-way-to-boot-iso-image-from-your-hard-drive-in-ubuntu-13-04.html
http://michael-prokop.at/blog/2011/01/07/booting-iso-images-from-within-grub2/