Is there any way

[alexxxxx]

I can install Ubuntu onto a flash drive and boot off that. My dad doesn't want me messing about with the new laptop, which is an incredibly slow-feeling VISTA machine.

[Splinter]

Dont think you can with ubuntu. Try slax.

[Eric30]

I think u can,
I tried it once, but wasnt successful, only because i was rushing it

http://www.pendrivelinux.com

[Colin-Roberts]

you can with dam small linux google it.

[DaveTaylor]

You can do it with any distro, a USB is now counted as an external hard drive is large enough, however it will be slow, also make sure your bios can boot from USB before hard drive at all etc