Before Safari 6, you could navigate to a URL with having to type ".com". The same can be done in Safari 6 with one extra keystroke.
Entering "apple" in the location bar of Safari 6 will yield you Google search results for those terms. However, including a trailing slash will cause Safari to add the .com TLD to a logical location in the address, and take you to that URL. So, "apple/" will take you to apple.com.
[kirkmc adds: This is fine, if you're trying to get to .com sites. If you're in a country and want to get to local sites, it won't help you. It's worth noting that you can enter any number of slashes and still get this to work.]
Update: As per a comment below, here's how to make it work when you type a /. For example, if you type "apple/ipod/" Safari will go to www.apple.com/ipod, if you do the following. Go to System Preferences > Network, click on Advanced, then DNS. In the Search Domains section, click on + and add .com. Click on OK, then on Apply.
Mac OS X Hints
http://hints.macworld.com/article.php?story=20120919001200353