Before I forget it again… To install pine from the Debian sources just do the following:
# apt-get --only-source build-dep pine
# apt-get --only-source -b source pine
# dpkg -i <packagefile>
You need to have the matching deb-src lines in /etc/apt/sources.list.
The first command will install the the dependencies needed to build, the second will get the sources and build a the package file in /usr/src/ which can be installed with the last one then.
To choose from stable/testing/unstable just add -t stable/testing/unstable to the apt-get lines.
An easy way to keep the latest version, is to install the pine-tracker package.