PE Builder v3 plugin
With this plugin you can get the GNU Unix utilities compiled for Win32 on your CD.
These utilities are put into the bin directory on the CD, which seems to be in PATH by default with PE Builder v3.1.10a, so you can run them straight from a cmd prompt.
I've left out a few files from under usr, so bison and flex probably don't work; however taking into account the nature of BartPE, software development work probably isn't what you're going to do.
If you downloaded the nofiles version, copy the files from the usr/local/wbin directory of UnxUtils.zip to the bin subdirectory of this plugin directory. Copy here also sh.exe from the bin directory of the zip file.
This plugin will take about 6 MB on the cd.