Security experts say we should use a variety of passwords and change them often. So how to remember them all? Two types of products can help. Symantec's Norton Password Manager ($39.95, uses software to store your passwords for Web sites and programs. When you browse a password-protected site, a little box pops up in the lower right corner of your screen. Just click on it and in you go. American Power Conversion's BioPod Biometric Password Manager ($49.99, and Sony's Puppy ($99.99, give you access to your passwords by scanning your fingerprint. Just touch the mirrorlike window on the pad and the program supplies the appropriate password. It does take some practice to put your finger on the touch pad at just the right angle. But it beats racking your memory--or playing trial and error.