Is there any way I can mirror a dropbox folder to my C drive by just running a portable file?

Extra background information because I know you guys hate it when you don't get the entire situation:

I go back to University in fall and I need a new storage solution. I decided to use DropBox to sync my tiny University files (< 5 MB). I need to access these files from 4 machines:

1. Windows 7 Home machine
2. Windows 7 University A machine
3. Windows 7 University B machine
4. Android tablet

1 and 4 are a non-issue. The problem lies with 2 and 3.

I want to be able to edit my files on 2 and 3 but those machines are not mine. There is an easy fix. Run a portable version of the DropBox syncer on a USB drive. But the problem is that I don't want to carry a USB drive around with me all the time. In that case, I can just run the small portable DropBox syncer off the internet. But where will it to store the files? A temporary directory on the C drive. There is only one issue left: there are hundreds of machines that I will randomly use that fit in categories 2 and 3. My portable DropBox syncer will notice that the temporary directory is empty on each new PC I use and instead of downloading my DropBox folder to the machine, it syncs the other way around i.e. it deletes my entire DropBox. The solution is to mirror my DropBox onto the temporary directory before running the DropBox syncer.