USB booting :: boot linux for windows and linux for OS X



I have only recently discovered the DSL website, but I have been dreaming of booting linux from an old USB drive (128mb).  Now, my only problem is, I want to boot linux on my windows desktop AND my OS X laptop.

Would it be possible to boot a windows formated linux and a mac formated linux on the same USB device?

In other words, plug the drive into the windows system, boot up linux, do stuff (you know, that work thing), then unplug the drive, go to the mac system, plug it in, boot linux, and work some more?

Also, if this was possible, and I had two 50mb builds, I would have 28mb left, so I could save an open office file on the drive, and then open it again on the other system?

One final question.  Is Ubuntu a good choice of distro?  I am pretty good with computers, but completely new to linux.
I dont' understand if you want to:
a) boot DSL (or any distro) natively from a PC and a MAC, or
b) boot DSL embedded from Windows on PC and OS x in a MAc from Qemu or Q?

Case:
a) not for Mac
b)I  have never tried but there is a better Qemu for Mac OS called Q, you could (maybe) put it on same USB drive, configure it and run it in emulation.

Case b), check the Qemu forum:
http://qemu.dad-answers.com/index.php
option A please.

I want to BOOT into linux natively, I don't want to emulate linux in windows or osx (like a virtual PC sort of thing, right?  be running linux within my standard OS?)

Another part of my question is would I need two separate builds/partitions on the drive (3 if I want the extra space?), or could I run DSL on the two OS's with the same build?  If so, for the extra space partition, would it be a FAT32 partition and would I need to leave any more than 50mb in the linux partitions for extra programs or anything like that?



Thanks for the reply!   :D
oh by the way I already have the instructions for booting in OS X and windows.  These are the links.  They are from the same thread, but someone posted the OS X instructions on a reply on page 3.

Windows install instructions

Mac OS X install instructions (second post)


In preparation of getting this working, I'm starting the download of the iso.  I'm using BitTorrent to download it, and I was just wondering whether I should get the 2.2 or 2.2b.  What's the difference?

downloading from here

original here.