Github and Plugins

Okay, so even though I'm the only one developing my project, I decided
to create a github repo so I can develop on my desktop, personal
laptop or work laptop as I see fit. I committed everything using the
steps Ryanb showed on Railscasts, and it all looks fine. However, it
doesn't look like the things in /vendor/plugins got committed,
specifically restful_authentication. That folder, while present on
github, is empty.

I eventually got it working by reinstalling restful_authentication as
a plugin on the second machine, but is that normal practice, or did I
do something wrong when I was putting my code on github?

it should commit. does your .gitignore file have a rule preventing it?