Spiff is a little GPLed program I wrote to handle packaging under Linux, it's about 3KB in size (the tarball package is 3KB, with readme, setup script and program) and it can handle RPMs, source tarballs and apt-get. It was initally made to automatically uncompress, configure, compile and install .tar.*z source packages. It is invoked at the command line, like so:

spiff (package tag) (filename without extension) (other options)

Its main other strength is that, unless you tell it not to, Spiff installs source packages into the /usr/spiff/ dir, giving nice easy centralised installation.

The name, if you're interested, stands for Simplifying Packages In Four Formats and you can download it from http://www.vjoebaldwin.co.uk/spiff/.