is dual booting on pen drives possible?

[c/Kr3t]

i've got both ubuntu and backtrack 3 on my pen drive but when i boot into it, it just boots to the most recent one installed (bt3). is there any way to setup dual booting on pen drives?

[Mighty_Joe]

Does Backtrack 3 use Grub for a bootloader? If it does, it should be as easy as adding an entry to the menu for your Ubuntu partition. Grub documentation here (http://www.gnu.org/software/grub/manual/html_node/index.html)
If Backtrack has overwritten Grub, you should be able to re-install it onto your pen drive and create entries for both OS's. Again, see the documentation linked above.