Two weeks ago, Corey Ehmke sent a pull request for some updates he made to the related_selects plugin on GitHub. Im actually quite late in pulling these but I have been extremely busy with work and family stuff. Here is what Corey said about the changes:
I made a couple of changes that you will hopefully incorporate:
1) Expanded support for include_blank to match behaviour of standard Rails form options helper. You can now pass an :include_blank attribute consisting of true, false (default), a string, or a two-element array, just like the standard Rails select form helper. If you do not set this attribute, the related select will default to the first option.
2) I also edited the README and replaced the original examples with the (much more concise and comprehensible) example from your post on angry-fly.com.
This is great! Thanks again for the updates Corey!