Installing multiple distros to a usb

[3lud13]

Currently I have ubuntu 11.04 installed on my laptop but am thinking of trying mint.
I have an 8gb usb stick which has my ubuntu distro on it which I used to install to my laptop now I was wondering if I could also put mint on the same usb without deleting ubuntu on it and have it come up with some sort of a bootloader like grub so i can choose which distro to load or will i have to erase the usb stick first.
and if it is possible to have them both on there how do i go about putting a bootloader on or will it just automatically be done when I burn the iso to it with the startup disc creator app.

[Neutrosider]

you can install distros and bootloader to usb sticks the same way you would install it on normal hard drives. if you speak german, this may help you:
http://www.pspking.de/forum/showthread.php?tid=49250

it's a tutorial i wrote some time ago. It explains how you can install a real ubuntu (not only the live system) and the ubuntu live system (to install it on another PC) to the same usb stick.

you just use it as Harddrive. In your case i would just make 5 GB or more unpartitioned space and then start the mint installer/live CD. then you just chosse the usb stick as installation destination and it will be installed there. make sure to tell the installer to install grub on the usb stick.

when you've done everything right, and you tell the pc to boot from the usb stick, you will see your bootloader.

[3lud13]

OK kind of what I want but I was just thinking having the live systems on the usb (also having the windows install files on there would be good just in case i require going back to it) then I can either run them from usb as a live distro or install them to computer (this would be very convienient as am getting a new laptop quite soon not to mention a new hard drive for this laptop also)
I did find a similiar post on the forums which I think is along the lines of what I am after but still currently reading it and getting a little confused.
http://ubuntuforums.org/showthread.php?t=1063834&highlight=multiple+distros+usb+key