The difficulty of memorizing multiple passwords and remembering which password goes with what account drives people to such practices as using the same password for multiple accounts. Others paste their passwords to their monitors with sticky notes. By encouraging such practices, the ceaseless demand for passwords can jeopardize the network security it is designed to protect. This situation is not likely to improve soon. Programs from different companies don't cooperate, so neither your e-mail post office nor your accounting system may understand that you have already logged in to the network.
Systems designed to provide a single login for all services are often very difficult to implement.
Over the longer run, things will get better, and passwords, which experts regard as the weakest link in network security, will become less important and may even disappear. Over time, what you are and what you have, probably in combination, will replace what you know. Perhaps the most widely used security devices today are tokens, like the RSA SecurID from Security Dynamics. The SecurID is a card or a key fob that displays a six-digit number that changes every 30 seconds. To log in to a system, you have to enter that number while it is displayed, making it, in effect, a password that is only used once.