Ok, I think I figured it out. For you Linux users who want to install the tar.bz2 binary locally.
1) download tar.bz2 from
http://sourceforge.net/projects/calibre/files/
2) extract to /opt folder. May help to delete the current /opt/calibre first.
3) run /opt/calibre/calibre_postinstall
this works for me. Now I can repeat this process for other Linux machines without having to re-download the binary. Hope this helps some people out there.
If any of you calibre developers have any suggestions to this method or warnings pls let me know.