*strong text*To put you into perspective: I'm no newby AND I'm close to nuclear meltdown.
I have tried to create a bootable USB stick using a 4GB stick and using the method with dd and the IMG file. The ISO was the AMD64. My mac is an older iMac white core duo (thus a proper 64 bit system).
I can create a DVD but it's later not bootable (I love Mac, really) and the same goes for an USB stick: DD works lovely, no error message but when trying to mount the darn thing it gives me a "not bootable" error and it will of course not boot from the thing.
It's not the medium as I have tried several stick and at least a dozen DVD and a few CD's too.
So, besides throwing the thing away and buying a proper PC is there any cheaper option?
Thanks.
BTW: I have Ubuntu working on an ACER ONE notebook.
The question was not asking how to start it from an USB but for an ALTERNATIVE to USB or DVD.
THE CORRECT SOLUTION:
The iMacs iMac5,1 (late 2006, Intel Core Duo 2.2, 17") have a bug in the EFI that does NOT ALLOW THEM TO BE STARTED from ANY EXTERNAL MEDIA that is not HFS+ (!!!!) No matter how many times you read the provided solution it will NOT BOOT.
ONLY an update to the LATEST Mac OS X Lion (10.7.5) and the implied EFI update will allow to boot from DVD/USB
– runlevel0 Feb 17 '14 at 13:40