A full install on a thumb drive

Much easier than unetbootin, and is persistent but takes a while.
I've done this on BT5 through the current Kali version.
The install must be done on a desktop, choose a fast drive if you only
have usb 2. the first step is to disconnect any and all hard drives by
removing just the signal or power cable.
Boot from a good DVD with the USB drive in place.
With no hard drives onboard the installer will only see the USB drive
and will allow it as a selection. This will not happen with internal drives
in place. Begin the install then choose erase and use the entire drive when prompted.
Takes around 1/2 hour. boot times are similar to older sata drives.

I use full install to but i got another procedure to make it work.

I use virtualbox, livecd, usb.

1. Create new machine, no virtual hdd needed.
2. Use prefered settings, mount live cd, activate usb with filter of your drive.
3. boot virtual machine, and format usb to ext4 if needed. (some usb are not recognized in installer with fat32)
4. install as you would with normal setup. (takes a while depending on your usb specs)
5. done
6. boot new system (boot for me takes about 5-6 seconds)

I tried it on 5 different machines at home, no problems, updates works and system works. No bugs or errors so far.
Used this for about a year. and works on any os with virtualbox and usb support.

My main setup:
laptop
cpu 1.4gHz intel celeron
8gb ram
no cd/dvd drive
removed internal hdd storage.

Partitions:
about 26gb system. (all in one for ease of use with updates and limited space)
3gb storage (to save documents or smaller files, and to move files between other systems if needed)
no swap needed.