With their increasingly large capacities, USB flash drives are a viable option for users with modest backup needs. But they're easy to lose or break, and their small size makes labeling difficult. In addition, although USB drives with 16GB capacities are now available, they are expensive and hard to find.

Backups via flash are not as brisk as backups via hard drives, but they're faster than both optical media and online storage services. Speeds vary by the type of flash memory used. Many of the new flash drives have a speed rating, expressed either in MB/s for read and write speeds or as a number followed by an X, as in 80X; higher is always better. (Drives that say they're ReadyBoost-compatible work with Vista's technology of the same name, which improves system performance but has no bearing on backup speed.) The drives we tested were fast to read data but slower to write. Backing up 1GB of data took anywhere from 1 minute for the media files to 25 minutes for the directory of data files. Reading data took 35 seconds to 2 minutes. Using our earlier formula, backing up 8GB of music would take 8 minutes and 8GB of text files could take as long as three hours and 20 minutes. The drive we liked best was the Corsair Flash Voyager 8GB, $100. It wasn't the fastest drive we tested, but it works with ReadyBoost, it is available in sizes ranging from 128MB to 16GB, and the price was good for an 8GB drive.