[plt-scheme] Beginner-friendly Net access functions?

Are there any library functions for net communication that have 
really simple interfaces, suitable for first-semester programming 
students?  I recall somebody talking about a classroom exercise in 
which students could send messages to one another, but now I can't 
find that discussion in my files.  And it should be simple to open a 
specified URL as an input port.
-- 
					Stephen Bloch
					sbloch at adelphi.edu