Dropbox offers cloud backup with a difference. I've tried a number of cloud backup solutions, including Carbonite, but never felt completely happy. Most offer backup and selective restore for the user folder, but none (as far as I am aware) does what Dropbox can do. Dropbox seamlessly and effortlessly synchronises your computer data with their cloud servers and then with any other computer you own or designate. Instead of trying to back up your existing data folders, you simply move your computer's data into the Dropbox folder (which can sit anywhere in your system; I prefer to have it on the desktop for easy access) and the rest is automatic.
There are no disks to mount, no connections to worry about. You have a full set of data on your computer as usual but with the difference that everything is duplicated to the Dropbox server. After two years of increasing reliance on Dropbox, I have now taken the decision to move everything into the Dropbox folder – including iTunes and iPhoto.
I now have Dropbox installed on all my Macs and on my iPhone so everything is available at any time and anywhere. My 1Password data file is there, so all my secure stuff is up to date on all my computers, all my documents and spreadsheets are there. The beauty of this approach is that I am working on the same up-to-date files wherever I happen to be.
Of course this works well for me because I'm the only user. This isn't a multi-user system so you can get sync problems if documents (especially the iTunes and iPhoto libraries) are open on more than one machine. As long as you remember to close your applications before changing to another computer there are no problems.
The sheer convenience of always having all your current material available from anywhere is matched only by the confidence you gain from having your data immediately backed up off-site. Dropbox isn't an alternative to a good backup strategy to cover disk failure or other disaster, but as part of a total data security solution it is ideal. In the event of a house fire or other catastrophe, all you need do is install Dropbox on any computer, put in your password and all your precious data comes flowing back to you.
All these benefits would come to nought if there was any hint of unreliability. Yet in two years I have never had the slightest worry or problem with Dropbox. It works away in the background and I find all my stuff is safe and up to date. It can be relied on utterly and that isn't something I'd say lightly.
Dropbox is free as long as you don't want to store more than 2GB. Up to 50GB costs $99 a year ($9.99 a month) and 100GB is $199 ($19.99). It's a small price to pay for total peace of mind and convenience. It works on Macs and PCs and there are apps for iPhone, iPad and, I believe, other mobile platforms. Bear in mind that the mobile apps give you access to all your files but you need to download them as required, for obvious reasons. You would hardly want all your data syncing with an iPhone, so selective download is preferable.