Carbonite

Carbonite earns a number of recommendations and awards from experts, who say it's incredibly easy to use and a great choice for simple online backup. Carbonite offers unlimited storage starting at about $55 per year, and it installs a software program onto your computer that automatically backs up new or changed files. The program works when your computer is idle so there is less drag on system performance. Reviewers say the backup process is unobtrusive, although several experts note that the initial backup can be very slow if you have a lot of data. The file marking system gets especially high marks because it provides an easy way to check a file's status. Each file and folder on your computer receives a small green dot in the corner if it's backed up; a yellow dot indicates the backup is pending, and no dot means the file is not backed up.

While Carbonite gets very good reviews for being easy to use, it offers few customization options, which may be a drawback for advanced users. One tester, Macworld, sees the lack of customization as a significant downside, especially since you can't set your own backup schedules. Carbonite has two versions -- one for Windows Vista and XP, and another for Mac computers running OS 10.4 (Tiger) or OS 10.5 (Leopard). Support for OS 10.6 (Snow Leopard) is expected in October. Some features, like versioning and file exclusion, are not included in the Mac version, although they may be offered in future releases. There is a 15-day free trial available, but Carbonite doesn't offer a free version. If you don't have a lot of data to backup, MozyHome Free will give you 2 GB of storage at no cost.

Carbonite is reviewed by a number of sources, but the best details come from Macworld, Web User, Computer Shopper (U.K.) and Which? magazine. All of these publications conduct comparative tests on online backup services, so you can see how Carbonite stacks up against competitors. The test at Macworld is especially useful since the editor has a different opinion on Carbonite than most of the other reviews we consulted. NotebookReview.com, MacWorld (U.K.) Mac User (U.K.) and PC Authority (Australia) also conduct thorough, but less comparative testing, ConsumerReports.org has a short report on Carbonite, but it's not subjected to their normal testing process.