From ToroSoft Software:
USB Flash Drive Backup protects all your flash drive files. Automatically backs up your USB Flash Drives when you plug them in. Works completely in the background so it doesn't interrupt your work. Schedule full and/or incremental backups. Incremental backup quickly backs up only the files and folders that have changed since your last backup. Restore your files from backup with ease. File preview makes it easy to select and restore only the files and folders you want. Don't wait until you lose your USB Flash drive.