Ubuntu 12.04 will fit on a CD, DVD, or 2 GB flash drive
I've downloaded Ubuntu desktop 12.04 and burned it to a CD, DVD, and 2 GB flash drive. On the CD it takes 715 MB, but it worked for me. I burned it with Nero. It takes about 5 min. to boot from a CD, 3 for a DVD, and just over 2 from a flash drive. Of course if your BIOS doesn't recognize the hard drive, no software will either.