Rapid Authentication Systems?

Barrington Johnson asks: "I am an emergency physician, and am looking for a solution for authentication which is compatible with rapid logons and logoffs. We have several web-based terminals into which we put information. The web application gives a real-time representation of the emergency department, so it is important that it is kept up to date. We have an opportunity to re-design our system, and I know that if I make the authentication process too difficult e.g. username+password, doctors will store up their data entry, and do it all in one go, removing the real-time usefulness of the display. At what level (application/browser/system) should authentication occur, and what method would be best?" Might a smartcard-based authentication system work well in this situation?