“Cloud computing,” like social networking (LinkedIn, Twitter, YouTube, et al.), is all the rage in this new era of distributed, collaborative, high-tech solutions to what are now everyday problems (some previously unknown until the time at which we arrived at a solution and forgot how we could have ever lived without them), and in the area of distributed, Internet-accessible file hosting, Dropbox reigns supreme.

Consider a fictional executive, Alice, who works frequently from home, and has a number of files that she needs to be able to access from both home and work. More importantly, she needs her files to stay synchronized between the two locations, so that if she updates an expense report at home in Upper Arlington she will have the up-to-date version when she arrives at work in Dublin, as well. Furthermore, while she is with her grandchildren in Manhattan, if she should realize that she forgot to record an expenditure, she needs to have access to that same up-to-date report.

In the past, Alice might have used a floppy disk, Zip drive, CD-RW, or, more recently, portable flash drive. But these media are susceptible to damage, and can be lost or stolen with relative ease. Adding encryption would keep Alice’s files secure, but at the expense of convenience and easy interoperability. She might choose, instead, simply to email the files to herself, but this solution is cumbersome, and sacrifices the ability easily to keep versions of her files in sync wherever she goes. Should Alice further discover that one of her fellow executives, Bob, also needs access to some of her files, both removable media and emailing herself become next to impossible to implement as workable solutions.

These types of problems are what Dropbox has been specifically designed to address. When someone downloads and installs Dropbox, the software (which includes a free version with limited but not insubstantial storage capacity) creates a special directory on that person’s computer (called his or her dropbox) which is linked automatically to the Dropbox servers. Any files placed in this folder are automatically backed up to Dropbox’s servers and stored securely and privately, accessible only that user’s Dropbox account. Whenever a file is updated, the Dropbox software updates it on the server as well, and since Dropbox detects what portion has been altered, the software does not transmit the entire file each time, but, rather, only the changes, making this process virtually instantaneous for most files.

Furthermore, the Dropbox software can be installed on multiple computers and linked to the same account, and whenever a file is updated (or added, or removed) in one of the linked locations, it is updated (respectively, added or removed) elsewhere as well. If a file is deleted by accident, Dropbox can bring the file back from the dead. If a change is made that is later found to be in error, the software allows the user seamlessly to roll the file back to a previous version. And, should the user use a computer that is not his or hers, Dropbox allows full access to his or her files through an intuitive, uncluttered web interface.

As if that weren’t enough, Alice’s desire to share some of her files with Bob are met by Dropbox as well. Our apocryphal user can place files in a “Public” folder, wherein he or she can create a special URL allowing anyone, whether or not he or she has a Dropbox account, to download and view the files. If more collaborative access is desired, one can create a “shared folder,” which allows any number of additional people with Dropbox accounts to have full access to all the files in the shared folder, all other features (version tracking, un-deleting, synchronization across computers) intact as well.

All of this is more easily experienced than explained. If you ever find yourself wanting to have access to certain files wherever you are, trying to keep track of something that needs to be maintained by multiple people in multiple locations, or even just wanting an easy way to back up some important files without having to worry about extra hard drives or stacks of disks, download Dropbox and give it a shot. You just might find that it solves a problem you didn’t even know you had.