Thereby I slackedpkg removed Firefox 2.0.4 and tar -jxvf 3.0.5 and I'd like to know where is target firefox directory in /usr/bin or /usr/local???
It will be wherever you extracted the tarball to in it's own self-contained directory. The firefox tarball does not make links in /usr/bin or /usr/local. If you want to do that, you have to do it by hand. In the past when I've installed a firefox tarball, I would just extract it in my home directory and run it from there. I haven't done this in a while but I believe the directory is named either "Firefox" or "Mozilla". Just go into that directory and click on the "firefox" file and it should start up.