Quick and dirty backporting technique
-------------------------------------

This example takes $package from Sarge and compiles them for Woody

/etc/apt/sources.list:
 deb     http://ftp.uk.debian.org/debian woody main
 deb-src http://ftp.uk.debian.org/debian sarge main

Prepare your system

 $ apt-get update
 $ apt-get install build-essential
 $ mkdir ~/src
 $ cd ~/src

Try compiling package

 $ apt-get build-dep $package

If $package is large/complicated then you will get:

 Build-Depends dependency on $package cannot be satisfied because the package
 $foo cannot be found

In this case you must recurse this procedure for the package $foo. If not then
continue.

 $ apt-get source $package
 $ ls

Locate the directory that $package has been unpacked into. It will be in the
form $package-$version.

 $ pushd $package-3.1
 $ fakeroot debian/rules binary

If 'binary' doesn't work, try 'binary-arch binary-indep'. The package will
be compiled and its binary packages will be created in the parent directory.

 $ popd
 $ ls

If $package is large/complicated then there will be several binary packages
(.deb files). If you are satisfying the build-deps of another package then you
only need to install the ones on which the other package build-depends.
Otherwise, install the desired binary package(s):
 
   $ dpkg -i $package_$version_$arch.deb
   $ dpkg -i lib${package}-dev_$version_$arch.deb
   .. etc