Here's a fun UNIX trick that I came up with while attempting to prepare a Ubuntu 9.10 tar file for a Solaris BrandZ installation.
Suppose that you want to monitor the progress of the creation of a tar file on a remote machine -- and you forgot to specify tar's -t option when creating the tar file. No problem! Use tail +1; e.g.:
tail -fc +1 ubuntu9_10.tar.gz | tar -tz