A rule of thumb is to check synaptic all ways first. If you install from a tar
ball or RPM. It may break the software you are installing and may be incompete.
Not all tar balls are going to work. Some need depends and you need to install
them as well. If a tar package. You can just left click on the package and till
the system to unpack here. Then read the install file if there is one.

http://monkeyblog.org/ubuntu/installing/

http://psychocats.net/ubuntu/installingsoftware