It's raining cloud services.
The problem: You have lots of files that you need to access from multiple places, and you don't want to rely on a USB stick or emailing yourself. The preferred solution, for years, has been Dropbox, the free cloud-storage service for seamless file syncing. But now, Dropbox has competition from a couple young upstarts named Google and Microsoft. Let's see how Dropbox, Google Drive, and Microsoft's SkyDrive stack up against each other.
Each of the three services puts a folder on your computer that you can drop files into, which in turn automatically syncs with the appropriate service's cloud-based online storage. Each service offers a variety of mobile apps for accessing your files on the go, and the ability to access and share files from the web. From that point of view, they would seem to be the same, but the differences in implementation are significant.
Dropbox is the service with which you may be most familiar. It's not the oldest (SkyDrive is), but it was the first to popularize this particular method of syncing files. When you install Dropbox on your computer, it creates a Dropbox folder with two gigabytes of free cloud storage. Files and folders you drag into the Dropbox folder are automatically uploaded to the Dropbox servers, but remain present on your computer, too. If you connect other computers to your Dropbox account, your files automatically sync with them as well.
If two gigabytes won't cut it, Dropbox offers paid options: You can spend $10 per month (or $99 per year) for 50GB, or $20 per month ($199 per year) for 100GB. If you get someone else to sign up for Dropbox with your referral link, you will both get an extra 500MB of free space.
Recent updates to Dropbox made uploading and sharing files even simpler. You can drag files directly onto the Dropbox website in your browser of choice to upload them to the service, and new sharing options make it delightfully simple to right-click (on a Mac, Control-click) on a Dropbox-stored file on your computer to expose instant and immediate public sharing options.
On your Mac or PC, Dropbox will superimpose tiny symbols atop your file icons indicating their sync status. That lets you know whether files are fully backed up to Dropbox, or still in the process of syncing.
Like its competitors, Dropbox also offers free mobile apps so that you can access your files on the go—from an iPhone, iPad, Android device, or Blackberry. The mobile apps, in addition to offering access to all your Dropbox-hosted files, also offer the option to cache certain files locally on your device; that way, if you're going to be stuck on a Wi-Fi-less flight, you can still gain access to your big presentation. While Dropbox's mobile apps aren't beautiful, they work well.
Oodles of third-party apps offer built-in Dropbox integration, too—you'd be hard-pressed to find a text editor for iPad that doesn't, for example. That's a distinct leg up over the other two services; Google Drive and SkyDrive don't have anywhere near that level of integration.
Check out our hands-on with the new Dropbox sharing features.
To use Microsoft's SkyDrive, you'll need a Windows Live or Hotmail account. If you use any of Microsoft's online services, including Xbox Live, you probably already have one. The SkyDrive app behaves an awful lot like Dropbox: It creates a custom folder on your Mac or PC that behaves just like a regular folder; drag other files into that folder, and they'll start syncing to SkyDrive automatically.
Microsoft offers seven gigabytes of storage with SkyDrive. For more space, you can spend $10 per year for 27GB, $25 per year for 57GB, or $50 per year for 107GB. Those prices are considerably more affordable than Dropbox's rates. For a limited time, old SkyDrive users can get a free upgrade to 25GB.
While it offers more (and more affordable) storage, SkyDrive can't quite compete with Dropbox's feature set. There's no option, for example, to right- or Control-click on SkyDrive-stored files on your desktop to generate quick sharing links. On the Web, however, SkyDrive's sharing options are excellent: You can quickly get a link to share your file; share it with the ability for the other user(s) to edit; post a link directly to Facebook, LinkedIn, or Twitter; and more.
Other limitations with SkyDrive right now include its very limited preferences: Where Dropbox lets you enable options like Selective Sync (where certain files and directories only sync to certain computers), on-screen notifications (about which files get updated when), and bandwidth usage settings, SkyDrive's preferences are almost comically limited. On the Mac, you get an option to automate the sending of usage data to Microsoft (off by default) along with an Open at login option; on Windows, you get the latter option, plus a second setting to "Make Files on This PC Available On My Other Devices."
On Windows, SkyDrive offers Dropbox-style icon overlays to show you whether your files are fully backed up or not. That doesn't happen on the Mac. Another Mac limitation: The SkyDrive app must sit in your Dock at all times; quit it, and your files silently stop syncing.
The SkyDrive mobile apps are very good, and available for Android, iOS, and Windows Phone 7. They look good and work well, offering quick access to recently updated files, documents shared with you, and everything you've synced to the drive. Again, as referenced earlier, few third-party apps integrate with SkyDrive; that may well change as SkyDrive's popularity increases.
For more details, see our hands-on with Skydrive.