Based on the comment:
Visited IPython Examples Using Chrome, right click on the notebook of interest, click 'Save link as...' and the .ipynb file appears in the IPython Notebook folder. Think I'm doing it right?
It's clear that you're downloading the whole webpage, not the notebooks. Following that procedure and opening the resulting file in a text editor, I get something like this:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title></title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<meta name="description" content="">
<meta name="author" content="">
<!--NEW RELIC Start Perf Measurement-->
<!--NREND-->
<!-- Le styles -->
<!--<link href="/static/css/bootstrap.css" rel="stylesheet">-->
...
What you need to do is follow each link to it's nbviewer rendering, and click the download link.
Alternatively, I would just download or clone the repository from github, change to the resulting directory, and start the notebook server there.