Dear Mike,
Yesterday I upgraded my iPhone from 3.something to 4.0.1.
I synced my iPhone to my computer. Did the upgrade (which first wiped my iPhone clean). Then, re-synced my iPhone to my computer.
To my surprise, when I launched Pleco, all of my flashcards had been restored. This implies that the act of syncing actually backed up my flashcards. If I just periodically sync my iPhone to my computer will my flashcard database be safe? I was under the impression that I needed to do a backup and then transfer the backup file to my computer. But that certainly wasn't the case when I did my upgrade to 4.0.1.
John