Four of the world’s biggest companies would seemingly do anything to give you gigabytes of free space on their servers. For anyone who remembers that 5 GB of slow, hard-to-install hard drive space cost $250 in 1998 , this feels mighty odd. And as if the future has arrived. But it might also leave you wondering which version of the future will best suit your needs.
The big players with the cheap plans and widely available tools for personal data are Amazon’s Cloud Drive, Dropbox, Google Drive, Apple’s iCloud, and Microsoft’s SkyDrive. There are many others, but among them, only SugarSync  and SpiderOak  have anything close to the right mix of universal access, decent pricing, and the ability to stand up against the corporate behemoths’ columns of optimized servers.
Which one works for you depends on what kind of stuff you create, how you want to get at that stuff, and how much you want to pay to have it available to you on a whim.
Straight-up pricing for storing stuff
If what you have is just a whole ton of stuff--super-high-res images, music, massive work files--that you just needed to prevent from dying in a fire, then pricing is pretty easy to suss out. Below is a breakdown of each major service’s pricing. If you need more than 100 GB for your own use, Amazon and Google Drive can help you out, while Dropbox offers 1 terabyte (1,000 GB) in its Teams pricing.
Cost per year
|Amazon Cloud Drive||Dropbox||Google Drive||iCloud||SkyDrive|
|Free amount||5 GB (plus 20 GB with music purchase)||2 GB (expandable to 16 GB)||5 GB||5 GB||7 GB (or 25 GB for existing users)|
|20 GB||$20||$29.88||$40||$10 (for those without free 25GB upgrade)|
For a more full accounting of what every notable cloud storage company offers, and for how much per gigabyte, check out Ars Technica’s perfect chart .
What stands out is how much SkyDrive gives away for free: 7 GB to everybody who registers an account, and 25 GB for people already holding a Live/Hotmail account who enable the free upgrade . SkyDrive is also the cheapest per gigabyte of the services that can sync to your desktop or phone. If you desperately need space and peace of mind, you can thank the world’s billions of Office users for subsidizing Microsoft’s slash-rate pricing.
Google customers who previously purchased extra storage from the Goog can similarly keep their cheaper space , at least for one more yearly billing cycle.
The hidden talents of each service
iCloud, well, it does something very specific for Mac and iOS owners  (and technically Windows iTunes users, but that’s just untenable). But each of these services does something more than you might know.
Dropbox: That huge range of 2 GB to 16 GB for free accounts? You don’t need to convince 28 friends to sign up for Dropbox at 500 GB each. You get an extra 3 GB right off the bat if you enable automatic photo and video uploading . After that, you can often get that valuable extra space for the price of a cheap-ish sandwich using Google AdWords , among other tactics .
The simplicity of Dropbox lies in its “magic folder” nature, but if you want to sync other folders, like your documents or certain projects, or even your Desktop as a whole, it’s not that tricky. Grab MacDropAny  (Mac) or Dropbox Folder Sync  (Windows), then point, click, and rest easy.
Google Drive: Want to send files to Google Drive without having to drag-and-drop to the Drive folder? Try a handy right-click trick  that makes its a two-step process to offload any folder in Windows over to Google’s cloud.
SkyDrive: Beyond the big free space and cheap paid space, SkyDrive has one killer feature, especially if you’re using mostly Windows systems: “Fetch.” That is, if you forget to sync something up to your SkyDrive from one system, then land on the other system to find it missing, you can remotely access your other computer and grab that file .
Amazon Cloud Drive: On its own, Cloud Drive is just a website where you can upload files, and then later download them. With third-party tools like Gladinet  or GoodSync , you can use Cloud Drive in the same “magic folder” style as its competition.
It’s also worth noting that once you pay the minimum 20 GB of Cloud Drive space, Amazon offers to host an unlimited amount of your music for free . That’s a major calculation for some folks, especially given that you can then play that music in any browser, anywhere.
iCloud: iCloud  is not like the others, in that it’s very specifically an Apple service meant to automatically sync specific things: contacts, photos, apps, documents, music, calendars, and the like. But designer John Marstall found at least one way to use iCloud photos a bit more freely than Apple design. His Photo Stream hack for Macs  lets you quickly pull out any photo from your stream for easy grabbing.
Which service do you choose?
It’s truly going to depend on your needs, but more so, the needs of your data. Me, I’ve split my online storage across three services: photos on Google Drive (because Google+ and Picasa also have nice-looking, easy-to-share web albums), music on Amazon MP3 (because $20 for unlimited MP3 storage is more than reasonable), and Dropbox for things I’m working on (because it has clients for every system and phone and tablet around). But that works out only because my wife and I mostly shoot photos with our phones, I don’t mind adding my music album by album, and most of my work involves writing tiny text files or working in Google Docs.
Don’t be afraid to split your backup across services, but also make sure you know how you’re going to get your data out once you’ve got your data up in each company’s cloud.
[Image: Flickr user Himmelhoch ]