Low level format program for Linux?

"Low-level formatting" isn't really done anymore. Older hard drives (MFM, RLL, some fairly ancient SCSI) could be low-level formatted. That meant that the underlying structure for the sectors was (re-)created. Some media (platter surface) errors could be rectified during the process, but the general idea was to prepare the drive to be "high-level formatted" by the operating system that you wanted to use (as in the DOS format command).

I guess you're after a "zero-fill" utility that will write zeroes to every position on a hard drive to erase data or in the hope it will correct a bad sector (which it sometimes will).

Such utilities are usually run from a bootable media and not from within your ordinary O/S. The Ultimate Boot CD has a number of such options and I can recommend that download for other reasons, as it has a lot of useful tools.
/RID

Is your ultimate aim to wipe all the data from the disk?

Not primarily to wipe data (although that is an obvious consequence), but to make my usb key automount under Sabayon Linux.  I was following the steps on the following page...

http://wiki.sabayonlinux.org/index.php?title=HOWTO:_USB_pen_drive_will_not_automount

which requires the usb key to be low level formatted as I was having this particular problem.  I have already gotten access to a windows machine and low-level formatted the key... which is now working well under Sabayon Linux.  I am just wondering if there is a Linux equivalent to low-level format.

You in fact want http://home.comcast.net/~SCSIguy/SCSI_FAQ/RMiller_Tools/scu.html
the SCSI Command Utility (scu).  You can even reformat drives with 520 bytes per sector (and extra 8 for checksums), and other esoteric tasks.

Also try http://sg.danny.cz/sg/ sg3_utils and sg_utils