Unpack Debian .deb package

I recently made the mistake of forgetting the upgrade process required from Debian Etch to Squeeze which almost trashed a remote server!

Fortunately I only broke dpkg prior to anything else so only required me to unpack the old version over-top of the newer one.  I thought others might like to know this one-liner also.

ar p dpkg_1.13.26_i386.deb data.tar.gz | tar xzv -C /