If you use Firefox, try this.  Next time you want to go to a site (e.g., http://www.cnn.com),just type the main name (e.g., cnn), and then press Ctrl+Enter, and Firefox will take care of the rest. If the site is something.something.net, do the same thing but press Shift+Enter. For .org sites, use Ctrl+Shift+Enter.

For many more Firefox keyboard shortcuts, check out this lifehacker post and this page from Mozilla.