Grant Rettke has his own take on a function to enable narrowing to multiple regions of a buffer. I learned about the idea from comments to a post on another matter and wrote about it here. Rettke takes the example functions that I wrote about and adjusts them to suit his own needs.
I really like that this idea is getting more exposure. As Rettke says, all the ideas are there in the Emacs manual but it takes guys like Zane Ashby to see how they can be used to solve a particular problem. I also like Rettke’s characterization of the problem as a sort of “semi-literate programming.” It seemed strange when I first read it but that’s exactly what’s going on: you can treat different parts of the buffer in different ways to create a whole.
If you want another take on the functions that Zane and grayswx wrote, head on over to Rettke’s post and take a look.
Update: Retkke → Rettke. Sorry Grant.