Live USB-Backtrack & reserve space for personal storage

view story

http://askubuntu.com – I have a 8 gb USB that I intend to use as a live USB but also have space for personal storage. After formatting, the USB has ~7.5 gb in fat32; I'm devoting 6 gb to the live USB and 1.5 to my personal storage. Also, I want to use the live USB as a functional OS. I've searched online for advice to such a problem, but found conflicting results. Some questions I have: Do I partition my USB drive? If so, then how many partitions and which formats? Some sites suggest a ext4 partition, is this needed? If I want to access the personal storage from the live USB OS, then what do I need to do? (HowTos)