Gmail users will soon no longer need an Internet connection to access their in-boxes and write and send messages. Within the next few days, in an ongoing push to bring cloud computing to the masses, Google will introduce a new experimental feature in Gmail Labs called Offline Gmail. This feature synchronizes e-mail from a user’s computer with Google’s servers when she’s online, and still provides the look and feel of Gmail when she’s offline. It relies on Gears, a downloadable piece of software that synchronizes and caches data for Web applications like Google Docs and Calendar.

From Google’s blog post:

Once you turn on this feature, Gmail uses Gears to download a local cache of your mail. As long as you’re connected to the network, that cache is synchronized with Gmail’s servers. When you lose your connection, Gmail automatically switches to offline mode, and uses the data stored on your computer’s hard drive instead of the information sent across the network. You can read messages, star and label them, and do all of the things you’re used to doing while reading your webmail online. Any messages you send while offline will be placed in your outbox and automatically sent the next time Gmail detects a connection. And if you’re on an unreliable or slow connection (like when you’re “borrowing” your neighbor’s wireless), you can choose to use “flaky connection mode,” which is somewhere in between: it uses the local cache as if you were disconnected, but still synchronizes your mail with the server in the background. Our goal is to provide nearly the same browser-based Gmail experience whether you’re using the data cached on your computer or talking directly to the server.

According to the post, Google employees have been using the feature for quite some time, which isn’t surprising, as most new features get test-driven by Googlers long before they are released to a wider audience. For a glimpse at the future of computing, it’s helpful to look at the habits of Google employees.

Of course, the cloud-computing push isn’t unique to Google. Adobe offers AIR, a platform to turn Web applications into software that feels as if it’s running on a computer’s hard drive. And Microsoft, for its part, is trying to make an operating system that plays well with the cloud.