Bootable USB thumb drive? Windows, Linux?

[Fox11]

I spent a day or so scouring the internet for information on how to boot an OS off of a USB thumb drive on a Macbook Pro, specifically my Santa Rosa MBP (3,1). What I'd like is a portable OS (Windows, Linux, whatever) that will boot both on a PC and on a Mac so that I can take it with me and use it with pretty much any computer. I tried rEFIt, which would get me all the way to choosing to boot off of the Ubuntu OS I installed on the USB stick, but then it would give me an error. I looked into GRUB2, but it's a little over my head.

Is this idea of a portable OS possible right now, or should I just give up?

 

[Winni]

You can do it with Linux, of course. Here's some documentation for Ubuntu Linux:

https://help.ubuntu.com/community/Installation/FromUSBStick

Windows Vista and Windows 7 don't support that, but some folks have done it with Windows XP. But I'm pretty sure that you will run into software activation issues when you change the hardware constantly (unless you run a volume-licensed enterprise version of Windows).

http://www.ngine.de/article/id/8