For those reading this that may not know what Google Gears does allow me to give a little bit of background on the situation and explain how, in general, web applications work.
Web applications are different then the applications you run on your computer in two very specific and obvious ways. First, they are run completely in your web browser (Firefox, Safari, Internet Explorer, etc.) and you do not need to download or install any local files for the application to function. Second, the data that the application stores or edits is not on your local machine but rather saved "on the Internet". These may seem like very obvious differences but I’ve mentioned these two reasons because the paradigm has shifted overtime and Google Gears almost completes that shift.
One of the many mantras of "Web 2.0" applications has been to freely allow users of these applications to have access to their data both via an API and being able to "export" their data into various formats. These APIs afforded many developers to blur the line between desktop and web applications – such as being able to geotag your photos in iPhoto using Google Maps – but these solutions still required an Internet connection for them to work properly. Something also to note is the fact that these APIs are mainly used by developers and not by the users themselves so even though the data was portable, this fact hasn’t been exploited by the average user much, yet.
Enter Google Gears – which provides developers with the needed technology to make their entire applications portable not just the data. The first example Google chose to show off Gears with is Google Reader (a really great example). Google Reader, up until a few days ago, was a way to read your favorite sites by subscribing to their feeds but its use was limited to when you were connected to the Internet. Google Gears allows you to use Google Reader, at least most of the application, offline. You connect to the Internet, download your latest feed subscription’s updates, get offline, and you’re still able to read the feeds that you’ve cached on your local system. What’s more is that you are able to flag those items and Google Reader will sync with your Google Reader account once an Internet connection is available.
In short; Google Gears brings your favorite web applications to your local computer and allows them to run almost like desktop applications.
Why am I excited? Because my main reason for not using some of the most popular web applications has been because I can not use them offline. I am a firm believer in having all of my data available to me at anytime. Unfortunately in some cases, such as my photo and music libraries becoming larger than my laptop’s hard drive, I’ve had to make sacrifices. However, when it comes to much smaller yet more important pieces of data such as email messages, bookmarks, and important documents I can not afford to make those sacrifices. As Google Gears is adopted and implemented in more web applications I’ll be able to begin using them offline.