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.