<p>For my school work, I do a lot of switching computers (from labs to my laptop to the library).  I'd kind of like to put this code under some kind of version control.  Of course the problem is that I can't always install additional software on the computers I use.  Is there any kind of version control system that I can keep on a thumb drive?  I have a 2GB drive to put this on, but I can get a bigger one if necessary.</p>

<p>The projects I'm doing aren't especially big FYI.</p>

<p><strong>EDIT:</strong>  This needs to work under windows.</p>

<p><strong>EDIT II:</strong>  Bazaar ended up being what I chose.  It's even better if you go with TortoiseBzr.</p>

The best answer for you is some sort of DVCS (popular ones being
Git
,
Mercurial
,
Darcs
,
Bazaar
...).  The reason is that you have a full copy of the whole repository on any machine you are using.  I haven't used these systems personally, so others will be best at recommending a DVCS with a small footprint and good cross platform compatibility.