Version 5 of the online backup service Carbonite Home ($59, 15-day free trial) offers some new and possibly handy functionality in two new tiers of service. Otherwise, it remains the same affordable, easy-to-use, but sometimes restrictive service we reviewed last year.

The two new tiers of service are HomePlus ($99) and HomePremier ($149). HomePlus adds the ability to back up external hard drives attached to your PC, as well as to create an image of your system to a local hard drive. HomePremier has those features plus a courier service. In addition, HomePremier doesn't impose the automatic video file exclusion that the two cheaper plans do.

Under HomePremier's courier service, Carbonite will overnight a physical copy of your data to you for quick restoration. One of the bugaboos of online backup is that, though it's a safe and convenient way to maintain offsite backups, it's extremely slow to restore over most Internet connections. Of course, if you have a recent local backup, restoring from that copy is even faster.

Carbonite's ability to back up external hard drives attached to your PC may be the most useful new feature. No longer having to copy data onto a internal hard drive to back it up could save you a lot of time. Whether that's worth $40 a year depends on how much you use external storage. It's certainly preferable to keeping important data on an external drive and not backing it up--a data no-no.

The ability to create a backup image of your system is convenient, but that functionality is already available for free within Windows Vista and Windows 7, and via programs such as Easeus ToDo Backup Free and CloneZilla. It might be handier to provide a secondary, local destination for the main backup to a hard drive, as CrashPlan, SOS, and others do.

I remain enamored of the Carbonite selection interface, which is tightly integrated with Windows Explorer. Right-clicking to add items to the backup job and scanning the colored dots on file icons to determine the backup status of each file or folder are great timesavers. So is the Carbonite drive found under My Computer, which lets you easily see what is being backed up and what has already been backed up. The friendly reminders that appear if your backups don't succeed for a few days are handy, too.

Less endearing is Carbonite's inability to alter backups or settings while a backup is paused, its quirky placement of some features, and the need to select video files, executables, and files with sizes greater than 4GB manually with the lower-tier services.

Carbonite's basic Home plan remains a bargain at $59. The appeal of the HomePlus and HomePremier plans depends on your current backup strategy. If it already includes a local component--not so much. But if you want a one-stop strategy, they may be worth a look.

Note: This link takes you to the vendor's site, where you can download the latest version of the software.

--Jon L. Jacobi