Alas, the cloud-tablet marriage hasn't worked out that smoothly, largely because tablet OS makers seem to have not considered cloud storage in their designs. Third-party services and applications are filling the void, helping users juggle a huge variety of file formats and object types. But tablet OS makers offer little or no built-in cloud support, which is holding back ubiquitous cloud adoption.
The problem is not just with Apple's iPad. Despite having a year or more of iPad experience to factor into their own development, the iPad's competing OS developers also haven't addressed this problem directly. Google's Android 3.0 "Honeycomb" edition, HP's WebOS for its forthcoming TouchPad, RIM's QNX-based BlackBerry Tablet OS for its forthcoming PlayBook, and Canonical's imminent multitouch Ubuntu 10.10 "Maverick Meerkat" all appear to lack specific cloud support.
The cloud storage apps step into the breach
Back at the dawn of the iPad (less than a year ago, believe it or not), Apple fan Robert Mozayeni queried Apple CEO Steve Jobs by email: "...I was wondering if there was any way to get my documents onto my iPad, through either iWork.com or iDisk?"
"Yes," replied Jobs, without elaboration. Apple did deliver on that implicit promise for both its still-beta iWork.com collaboration site and the MobileMe cloud service's iDisk virtual disk feature.
Alas, poor Mozayeni neglected to tell Jobs that he wanted to put the documents back after editing them on the iPad. Apple didn't deliver that capability until the November iOS 4.2 update, and in any event, the trick only works for subscribers of Apple's $99-per-year MobileMe service. Apple provides no interface to other cloud storage services -- you need an app for that.
There are in fact apps for that, with innovative solutions providing both an alternative to MobileMe's annual subscription and functionality beyond Apple's meagre MobleMe/iPad sync capability. These products cover a wide range of capabilities and prices, with a visible trend toward extra-cost business-class features such as collaboration, encryption, support for multiple users, reporting, group permissions, and rebranding.
These mobile cloud services predate the current tablet craze, by dint of being launched two or more years ago to provide convenient file sharing among desktop users or to deliver bulk enterprise-class cloud storage. They've also been serving cloud storage capabilities to smartphones. As a result, numerous developers have incorporated access to these third-party services in their smartphone apps, many of which also run on tablets.
The cloud storage service providers include big guns such as Amazon.com's Simple Storage Service (S3), Apple's MobileMe, Google's Google Docs, Microsoft's Live Mesh/SkyDrive, and Rackspace's Cloud Files. Users generally don't interact directly with these providers from their tablets, but instead work with an intermediate provider such as Box.net, Dropbox, JungleDisk, Soonr, and Spot Documents. Some intermediaries also offer their own apps for iOS and Android devices, and there are several cross-cloud storage apps, such as CloudConnect Pro and SMEStorage. Plus, there are third-party apps that give tablet users access to SharePoint document collections.
Most apps are free, but you must pay a subscription to get access to the best cloud services. Although there are free teaser subscriptions available, tablet users seeking to make cloud storage their tablets' "hard drives" will need an intermediate plan that costs $5 to $20 per month for its larger storage capacity and file transfer budgets, advanced sharing capabilities, plug-in applications, and business-friendly features.