I was writing a reply to this thread about converting a Windows 8 ISO file into a bootable USB install setup, and all of a sudden it was locked, so I just decided to make a new thread. viewtopic.php?f=6&t=85774
Not sure why this was not discussed earlier, but Microsoft made a tool when Windows 7 came out that will take any Windows 7 ISO and write it to a USB key and make it bootable at the same time. It works just as well with the Windows 8 ISO(s) that I have tried and I tried it a bunch of times.
Whichever guide you use, don't forget to delete the ei.cfg file so you can stick to 1 image for home/pro/ultimate/etc. Not making that the default is the dumbest microsoft decision ever. (so many wasted downloads I'm sure)
Also look into adding the UEFI bootloader thing, its not hard and worth trying on a lot of modern systems. Its tricky to confirm you are actually in the proper install mode, and you really want to manually clean the disk and make sure it goes GPT yourself, but it can't hurt.