Ctrl + T. New empty tabbed window, ready to enter a url. Easy as pie.
WTF were the Firefox developers smoking when they did this?
Now you get an idiot message every time you open a new tab (like you wouldn't otherwise know that you opened a new tab, for heaven's sake!). Not only that, but there's a pre-filled URL that is not pre-highlighted. So when you reflexively try to type in a web addy after opening a new tab, you're unwittingly adding to text that's already in the box. So, you have to first highlight that text and delete it, before you can type in the url that you want. There is a box to click that states, "Don't show this page again," but you can click it a thousand times, and the same idiot message will continue to rear its ugly head.
You'd expect idiot messages like this in Internet Explorer; after all, newbies cut their teeth on IE, so maybe they need an idiot message to figure out what the hell they're doing.
But Firefox has long been the choice of many a web-savvy user, and web-savvy users don't need no stinkin' idiot message every time they open up a tab.
C'mon, Firefox--don't dumb down the web.