Question: I recently bought a Sandisk Cruzer USB drive. Part of the drive (6.66 MB) is formatted with CDFS and shows as a CD drive.

Why do they do this ? Is it to protect the software on that part of the disk to trick the OS (Vista) into not overwriting or amending, because it thinks this is a read-only CD ?

Is the 6.66 MB significant. Apart from being associated with the Devil ?

How can I format a partition on a USB drive to be CDFS ?

Why would I want to do something like that myself on my other flash drives ?

I'm a programmer, so how can I leverage this new knowledge ? Any Ideas ?

Answer: 
This is part of the U3 software that comes on it. It is garbage and I always remove it, the link for the removal tool is here:<http://u3.com/support/default.aspx#CQ3>

Keep in mind, this will format your drive.
Most likely the reason they did this was to prevent overwriting their software from the flash drive. 

If desired, you should be able to change the partition scheme to fully utilize the drive. The easiest way to do this is to boot into [a Linux LiveCD](http://www.ubuntu.com/) and use [gParted](http://www.wikihow.com/Use-Gparted) to fix it. Offhand I can't remember any [free partition managers for windows](http://www.google.com/search?q=free+windows+partition+managers).