run 'bunzip2 filenamegoeshere.tar.bz2'
this will put the tar file in to the directory where the bzip file is. then untar it using...
tar -xvf filenamegoeshere.tar
which will put it into your current directory.
I *think* you can pipe one to the other:
bunzip2 file.tar.bz2 | tar -xvf
but i've not tried it myself. .tar.gz files are much easier to unzip for future reference...
tar -zxvf file.tar.gz