What is the preferred way to install packages from testing/unstable in stable?

[Aniruddha <mailingdotlist@gmail.com>]

I would like to install the latest version swfdec-mozilla (because it
offers autoplay). I intent to track stable as closely as possible. As
far I can tell there are four possibilities to achieve this:

1) Temporary enable testing/unstable repositories and install the program
2) Download *.deb from packages.debian org
3) Use apt-pinning
4) Compile from source, this requires option 1 to be enabled.
Otherwise you get the following error:

# apt-get build-dep swfdec-mozilla
E: Build-Depends dependency for swfdec-mozilla cannot be satisfied
because the package libswfdec-0.8-dev cannot be found


I am interested to learn the best method to install a newer package
while remaining as close (compatible) with stable as possible. Thanks
in advance!