Dropbox is one of the most popular cloud-based storage systems. While we will be looking primarily at the Mac version, Dropbox is also available for Windows, Linux, and most mobile platforms, including iOS devices.

Once you set up a Dropbox account, and download and install the application, it will appear on your Mac as a special Dropbox folder. Anything you place inside the folder is automatically copied to the cloud-based storage system, and is synced with any other devices you use that are also running Dropbox.

This means you can be working on a document on your Mac, head off to work, and go back to work on the document, knowing it is exactly the same version as the one you were just fiddling with at home.

Dropbox isn't the only cloud-based storage and syncing service for the Mac, but it's currently one of the most popular. It does have some pretty stiff competition, though, including Microsoft's SkyDrive, Google's Google Drive, Box.net, and SugarSync.

You may notice a glaring omission from that list: Apple's iCloud. In its first release, iCloud lacks a general-purpose, cloud-based storage system, such as iDisk, which was included with MobileMe, the precursor to iCloud. If you currently use iDisk, you may want to consider Dropbox, or one of its competitors, as a replacement, at least until Apple again provides a similar service of its own.

Dropbox is available in four basic pricing plans; the first three let you expand the amount of storage you have by referring others to the service. For example, the basic free version of Dropbox will give you 500 MB per referral, to a maximum of 18 GB of free storage.

Dropbox Pricing

• Free: 2 GB, plus 500 MB per referral, up to 18 additional GB.
• Pro 50: $9.99 per month or $99 per year. 50 GB, plus 1 GB per referral, up to 32 additional GB.
• Pro 100: $19.99 per month or $199.00 per year. 100 GB, plus 1 GB per referral, up to 32 additional GB.
• Teams: $795 per year for 5 users. 1 TB of storage.

Installing Dropbox

1. You can grab the installer by downloading it from the Dropbox web site.
2. Once the download is complete, look for the installer in your Downloads folder. The file name is Dropbox version#.dmg. (At the time of this writing, the file name was Dropbox 1.4.0.dmg.) Launch the installer by double-clicking its icon.
3. From the installer window that opens, drag the Dropbox icon to your Applications folder.
4. Launch Dropbox, now located in the /Applications folder, by double-clicking its icon.
5. The Dropbox setup window will open and ask if you have a Dropbox account. I'm going to assume you don't, so select "I don't have a Dropbox account" and then click the Continue button.
6. Enter the requested account information, and the name of the computer you will be running this specific copy of Dropbox on. Click Continue.
7. Select a Dropbox service. I'm going to assume you want to start with the free version, so select the Free 2 GB version, and click Continue.
8. You can use the typical setup, which will create the Dropbox folder in your home directory, and sync that folder with all of the folders in the Dropbox cloud service. You can also select the Advanced setup, which lets you select the location for the Dropbox folder, and the folders you want to sync to. But because you can change these settings at any time, I recommend selecting the Typical installation option for now, and then clicking Install.
9. The Dropbox installer provides a quick summary of how Dropbox works, including a tour. You can use the Continue button to take the tour, or click Skip Tour to finish the installation. If this is the first time you have used Dropbox, or any syncing service, I suggest taking a moment to go through the tour. Click Continue.
10. Once the tour is over, click the Finish button to exit the installer.
11. Dropbox may ask you to supply the password for your home account on your Mac; this is necessary for Dropbox to update the folder it creates in your home account. Supply the password, and click OK.

Your Dropbox folder is now working. You'll find a Dropbox item in your Mac's menu bar, and if you look inside the Dropbox folder you'll find a Getting Started PDF that will guide you through the basics of using Dropbox.

One last thing. While you can always access your data from the Dropbox web site, it's easier in the long run to install Dropbox on all the Macs, PCs, and mobile devices you use.