You could try
tar -tvf /dev/st0
which should list the filenames (t = table of contents)
or tar -xvf /tmp/test /dev/st0
which should extract the files into /tmp/test if you want to compare sizes/checksums etc.
Make sure the tape is rewound first.
I've tended to use taper (http://sourceforge.net/projects/taper/
) as it has a nice (curses) based interface and is pretty stable. It's up to v7.
I suggest you try it out as it's free.