need help with redirection

I want to create an web application that will link up a student's
facebook, twitter and orkut accounts all under one shed. Its like
connecting all the students within a college, to login into the web
app, the userid will be the unique studentID provided by the college
Now, once a student has logged-in, he can open his facebook, twitter
and orkut a/c in the same window, lets say under tabs. How can i do
I mean how can i pass a student's Facebook's user-id and password to
facebook server and if user authentication is done, then show the
student his facebook wall.
I am very confused and don't know how to deal with this.

Twitter & facebook both have apis that allow you to get at the user's
streams. You don't send their password though - a mechanism called
OAuth is used to get you a token that allows facebook etc to know that
the user has granted your application permission to access the user's
data (with various levels of granularity)