[CentOS] Resizing a fat filesystem on a USB partition

Hi All,

I feel this is the most simple question but I am currently going around and round in circles and searches keep bringing me up Windows tools!! :-(

I have a 512MB USB drive that has a 12MB FAT16 partition on it. How can I resize this 12MB partition to grow and fill the whole 512MB drive?

Just in case I am being stupid, here is what I am doing... :-) I would like a quick USB drive that a machine can boot from but will then load and run some custom tools we have. I have done a... dd if=/mirrors/centos/5/os/i386/images/diskboot.img of=/dev/sda ... which gives the 12MB partition but now I want to grow it so I can then add my own apps.

Thank you very much in advance

Regards, Dan