Wear outdoor clothes, grab a big black brush, and
Code:
tar cf /tmp/directories.tar name of directories
where
/tmp/directories.tar is the name of the tar file you want to create, and
names,
of, and
directories are, well, names of directories.
Usually you will also want to
gzip or
bzip2 compress the tar file; some tar commands even have built-in options to do that at the same time as creating the tar archive. Consult your local manual page for the gory details.