Security on Public Machines?

ThePopeLayton wonders: "I am currently a university student and unfortunately don't have my own computer yet. With all the key loggers and mal-ware out there, what can I do to keep my information secure. I probably log onto 20 different machines a week and changing my password, every two weeks, on all of my online accounts seems a little too much. What can I and other public computer users do to keep our personal information secret and safe?"