Between new kernels, patches, and source, I found myself doing:
tar jvxf filename.tar.bz2
tar xvzf filename.tar.gz
all the time. So I wrote a script called unball to perform the same operations I was doing over and over... it recognizes bz2s, zips, gzs, tgz, rars, jars, and tars. Put the "unball" script in your path and the kdeunball.desktop script in your servicemenus directory. Its quite handy to type unball from the console instead of nineteen different options...