We've spent a couple posts (and will have plenty more in the future) talking about the benefits of web-based software. There are still some things, however, that web applications don't do as well as their desktop counterparts. We'll have another post giving an overview of some of these features later, but today I want to talk about one in particular: accessing the application and your data when you don't have an internet connection. While there isn't a general solution that lets you access every site when you're offline, a number of major web applications (including Gmail, Google Calendar, Remember the Milk, and Zoho Writer), provide offline access using a plugin for your internet browser called Gears. After installing Gears and changing some settings in the web applications, you can write an email, check your calendar, or check something off your task list from the comfort of your very own airplane (or cramped middle seat on a commercial airline).
Disclaimer: while it works well right now, Gears is no longer being actively developed by Google. As a result, some sites that currently use Gears may start using other methods in the future. That said, setting up offline access with Gears is easy, so you may as well try it out if offline access is a major thing holding you back right now. If nothing else, this can give you a glimpse at what new technologies can enable for web applications.
The first thing you'll need is to install Gears. If you're using Chrome on Windows, this step is already done (it comes preinstalled). Otherwise, make sure you have a compatible browser; most versions of Firefox, Internet Explorer, or Safari should work. To install Gears, navigate your browser to gears.google.com and click "Install Gears." Follow the prompts to install the software and restart your browser. Assuming all goes well here, Gears should be installed and ready to go.
The site that I most often need access to when I'm offline is Gmail, so I'll show you how to set up offline access for that site. Other sites work the same way for the most part, but let me know in the comments if you have questions about getting them working. With Gears installed, just login to your Gmail. In the top right corner of the page, you should see a "Settings" link. Click on that, and then choose the "Offline" tab. Choose "Enable offline mail for this computer" and save changes. You can always come back to this page later to change settings about how much of your mail is available when offline.
After saving your changes, you should be prompted to give Gears access to Gmail. Gmail will then start downloading your mail to allow you to access it when your computer is offline. From now on, whenever you are online, your new messages will be kept in sync. Any time that you are offline, you'll be able to read old emails and compose new ones to be sent when you next have an internet connection. Essentially, you can now continue to use the web application just like you would a desktop application, and still get all the benefits that we've talked about previously from web software. This has been a pretty quick run through, but hopefully it gives you an idea about how easy it can be to use a number of web applications even when you're offline. Feel free to let me know in the comments if you have any trouble setting up Gears and I'll be happy to help out.