As for the type of partition it really is up to you.
There are pros/cons to each type.
I found this easier and quicker to use:
www infosecramblings com/backtrack/backtrack-4-usbpersistent-changesnessus]Backtrack 4 – USB/Persistent Changes/Nessus | Infosec Ramblings[/url]
I did have a strange problem. I first setup a 2gb USB drive using unetbootin. Everything was fine except I used the entire 2gb and could not save changes
Next I partitioned a 8gb micro SDHC card into 2 4gb partitions and followed the steps from the link above. For some reason when I used unetbootin to setup the first partition on the 8gb USB it would not create syslinux.cfg, so I could not boot to it. I tried it 3 different times but I could not get it to work. I copied the syslinux.cfg file from the 2gb USB to the 8gb USB root folder and all works fine.
another problem I encountered is that I have a couple of laptops that don't support booting from USB. The solution was to get plop boot manager and create a CD which can boot to the USB.
www plop at/en/bootmanager.html
Just a couple of small things from a BT noob but I hope they may help some people.
just came to a problem in BT4 with the usb install: a 4GB usb disk partitioned and installed BT4 as the video on remote-exploit guides seem not to be enough after the latests updates.
anyone else having the same problem? could this also means that something wrong took place during the partitioning/install?