cvs checkout question

We switched to using CVS from PVCS a few months ago, and so far I like it
a lot.  However, there is one thing that I can't find any way to do, and
would like
to know if it is even possible.  Can I just check out a single file, rather
than the entire
module?  When I specify a filename with cvs checkout, it says "cannot find
module
'filename' - ignored".  Sometimes I make changes to a file in my working
copy and
then decide they should be undone completely, or done in a different place
(e.g.,
on the trunk rather than on my branch).  In this case I want to overwrite
my copy of
that ONE file with a repository revision, but I don't want to check out the
entire source tree.  Is there any way to do this?

BTW, we are using CVS version 1.11.1p1.
Thanks very much.

-Ariel Canright