As you may know, the vast majority of browsers will guess at a full URL if you give them just a partial URL. Note that this isn’t the auto-complete feature, where the browser will fill in a URL that you’ve previously visited based on your typing. Instead, consider a site you’ve probably never visited, like … umm … maybe The Rest is Noise (www.therestisnoise.com), the blog of Alex Ross, the New Yorker’s classical music critic. (Not being a classical music aficionado, I asked fellow Macworld author Kirk McElhearn for a URL that I probably hadn’t visited before.)
To get to the above site, you could type the full URL, of course, but that’s a bit time consuming. So the shortcut method is to just type the site name portion of the URL, leaving off everything else: therestisnoise . When you press return, every major OS X browser will add http:// at the front, and .com at the end. That’s not much of a tip, though, as I think this behavior is well known.
What might not be so well known is that, in many OS X browsers, you can do the same thing to get to sub-pages of a given site. For instance, Alex Ross has a collection of essays on his site. If you wanted to jump directly to those via typing, you could just type therestisnoise/essays into the URL bar and press return. The browser is smart enough to add the .com before the first forward slash (and the http:// at the beginning, of course). This trick works in nearly every OS X browser I tried it with—the only exception was Firefox 2, which ignored anything after the slash and just went to the home page of the domain. But Safari, OmniWeb, Camino, Opera, and iCab all jumped directly to the essays page.
Note that some people have reported that this trick doesn’t work for them, regardless of which browser they’re using. I’m not sure exactly why it’s not working, though it might be related to each user’s DNS settings. So if it doesn’t work for you, sorry!
Obviously, if you visit a certain subsection of a site often, it makes sense to bookmark it for really fast access. But there are times, even with bookmarked sites, that I find it quicker and easier to use this typing shortcut—especially if both the URL and section name are short. As a real world example, I always type apple/macosx rather than navigating into my Bookmarks folder to find Apple’s Mac OS X pages bookmark amongst the 500 or so sites I have bookmarked.