Unlimited for £48/US$72 (around AU$83) per year
Livedrive is a capable service that seems to tick many of the online backup boxes. You get unlimited storage, for instance, plus Windows, Mac and mobile clients for iOS, Android and Windows 8 devices. Your files can be accessed from the Livedrive web interface, and a built-in media player enables you to enjoy your music and videos without having to download them first.
There are some limitations, though. The system only keeps the last 30 versions of a file, for instance (not as many as you think if your software saves documents automatically), while deleted files are lost after 30 days. And features such as syncing, file sharing and document editing are only available if you upgrade to the notably more expensive Briefcase account.
We weren't overly impressed by the backup client, either. It's a little basic, there are few configuration options (although the ability to limit upload and download bandwidth separately is useful), and restoration is more awkward than it should be. Switching to the web interface doesn't always help, either, since this only enables you to download a single file at a time.
There aren't too many compelling reasons to choose Livedrive, then - you'll probably be better off with one of its cheaper and more capable competitors.
2GB for free, 50GB for £54.89/$65.89 (around AU$95) per year
Every great online backup service needs a quality desktop client, and Mozy's for PC and Mac is better than most. Getting started is very easy, for instance, because there's no need to worry about choosing specific folders to back up (although you can). Just select one or more file types - pictures, music, bookmarks, email and so on - and the program will protect them for you.
A vast array of configuration options enable you to define exactly when the backup occurs (either scheduled or when your PC is idle), how much bandwidth it can take, whether backups run when a computer is on battery power, how the system integrates with Explorer, and more.
Restoration is straightforward, too. You can search the backup set by date, or for the latest version, or just restore your entire backup tree with a couple of clicks. Android and iOS apps give access to your data from anywhere, and there's a web interface too.
There are also issues. File versions are kept for only 30 days, for instance, plus there's no file sharing option, and most significantly, you get very little storage space for your money. If you don't need any more, though, Mozy's excellent software may appeal, and the company also provides a free 2GB account, which could prove useful.
2GB for free, 100GB for US$100 (around £65/AU$112) per year
At around twice the cost of Carbonite, SpiderOak is one of the more expensive services here - so is it really worth a look? Maybe.
Capacity isn't overly generous, at 100GB, but you can use as many PCs, Macs and Linux computers as you like on the same account. And there's no deleting old file versions after 30 days, either, since SpiderOak keeps them forever.
Security is excellent, too, with your backups encrypted so that nobody else can access them (not even SpiderOak staff). There are also impressively powerful synchronisation and file sharing features, and the system provides clients for Windows, Mac, Linux, iOS, Android and more devices.
There are also complications, though. The backup client is awkward, more difficult to use than most of the competition. It doesn't offer the same fine-tuning options you'll get elsewhere (scheduling is basic, and you can't really control its use of system resources). And we found performance was unpredictable - sometimes it was fast, sometimes it was slow, there was no way to tell how it would behave at any one time.