I came across a useful resource for working with a Western Digital MyBookWorld: http://mybookworld.wikidot.com . In particular, the instructions at http://mybookworld.wikidot.com/optware get you a basic package management program (along the lines of apt) which is what I’ve been needing. I’m installing nano right now (finally bu-bye vi and your crazy commands) with:

/opt/bin/ipkg install nano

and…yes, it works (after adding /opt/bin to PATH). Yay!

I had hoped to install openVPN as well. I found some instructions that are related, but, alas, I can’t figure out how to get the kernel-module-tun installed.