This bit of code tells browsers to go off to www.flickr.com and fetch the badge.js.gne file. There's a problem with doing it this way: if www.flickr.com is running really slowly, the file might take quite a while to download, and until it's downloaded, the rest of your blog won't display.
And here's how that looks in practice (a little broken in Firefox, I'm afraid!):
How it works: it hooks
document.write, it inserts the widget HTML straight into the DOM using
document.getElementById, using the ID specified at the end of the URL. 8113571 is a random number, just in case you have multiple widgets or other sites start using this code.
I'm just about to implement multiple widgets, so a single user on a PeopleAggregator install can configure several widgets. You could have one for each of your blogs, or perhaps more than one on a blog, if you wanted to show your friends at the top of your sidebar and your blog posts in the main body area. And of course, because of the new trick, it won't slow down your page load, even if the PeopleAggregator server bogs down or crashes.