Hello,
Just to report how I installed Ubuntu 9.10 Alpha 4 using my Pendrive. First I download it from http://cdimage.ubuntu.com/releases/karmic/alpha-4/
After this I used the "System - Administration - USB Startup Disk Creator", choosed the image that you want and press "Make Startup Disk".
Than just boot from the PenDrive and install normally.
Matheus
Ok, mas como fazer isso no Windows XP, você sabe???
Valeu.
Vinícius, talvez este artigo possa ajudá-lo:
http://digitalside.com.br/blog/2009/10/como-instalar-ubuntu-pelo-pendrive/
[]s