Google is shaping Gmail into the ultimate communications hub. Today, the company announced that United States users will be able to make and receive calls within Gmail, providing they install the company's voice and video plug-in.

Users could already call and video chat with other Gmail users, but the new features allow them to call landlines and cellphones. Google says that calls to phones within the U.S. and Canada will be free for at least the rest of the year, and calls to many other countries will cost 2 cents a minute.

Google writes:

We've been testing this feature internally and have found it to be useful in a lot of situations, ranging from making a quick call to a restaurant to placing a call when you're in an area with bad reception.

Google previously made a foray in Gmail-to-phone communication with an experimental feature that allowed users to send text messages to phones. It was a smooth, impressive step toward blurring the lines between the different forms of communication that people use on a daily basis. However, abuse of the system (including an iPhone app that piggybacked on it in order to provide users with free text messages) pushed Google to limit its functionality.

By adding the ability to call phones, Google is pushing to set Gmail apart from other webmail services, and it probably means other communications systems will be centralized within that interface.

Google staff engineer Adam de Boor gave a keynote this morning at Usenix WebApps '10 in Boston, where he outlined a few of Gmail's next steps. The webmail application, which launched in 2004, has aggressively added new features in the years since, and is currently launching as much as one new feature a week.

De Boor said that there's currently a big push at Gmail to figure out how to take maximum advantage of HTML 5, a standard Web technology that's been increasingly adopted by browser vendors. HTML 5 allows web applications to behave more like desktop applications, and Gmail recently started allowing users to attach files by dragging them into the browser window.

In the future, the company hopes to extend that by allowing users to download files by dragging them out of the window. By improving its applications this way (and by making complementary improvements to its Chrome browser), Google plans to show that Web applications truly can do everything desktop applications can do.

The company also plans to use HTML 5 to pursue its obsession with speed. In particular, Google's experiments with HTML 5 and the associated CSS 3 show that using those technologies could speed up Gmail's load time by 12 percent.

The company has also been researching a new model for Web applications that could speed up load times even more. In experimental builds of its Chrome browser, Google has started allowing users to install Web applications, meaning that the browser keeps a page for that application always loaded in the background. This means that the Web application always has up-to-date data, and is always just a click away. When the user types the URL for the application, the browser links the user to that preloaded background page, speeding up the time it takes to get to the service.

By applying this technique to Gmail, De Boor, said, the hope is to get the webmail application to load in under a second. Google's vision for the speed and behavior of Gmail is likely to set a standard for Web applications across the board.

This week's Gmail outage highlights the key problem with cloud computing: it means handing both your data and your infrastructure over to someone else.

Understandably, many businesses prefer to have more control. Struggling to repair an email server is, after all, marginally preferable to refreshing the Google maintenance page with both fingers crossed. So as Google tries to encourage more corporate customers to use Gmail, Google Docs, etc, expect the company to push the option to mirror data locally (something that's already possible through Google Gears). Microsoft has already announced that customers using the online version of Office 2010 will be able to store data in their own data centers if they choose.

Perhaps the retreat from the cloud dependence could go further still. Why not let companies switch back to using local servers whenever the main service goes down, as inevitably it will, from time to time. This might be technically difficult, but it doesn't seem impossible.

And, if your heart sank when Gmail fell it may be time to consider the benefits of an old-fashioned local mail server. Sure, you could spend hours configuring it or troubleshooting problems, but at least you'd know someone was working on the problem. And it would let you safeguard your own data and protect your privacy.

Danny O'Brien of the Electronic Frontier Foundation calls this "Living on the Edge" and argues that it may the best way to preserve certain freedoms in an age when more and more information is floating off into the cloud. (I saw him give an interesting talk on the subject at OpenTech 2008--you can see a rather shaky video of it here). For more on the possible dangers of cloud computing, also check out Cory Doctorow's latest column for The Guardian.