How to fetch a binary package given the package name

[Malte Forkel <malte.forkel@berlin.de>]

I can use
   apt-get source <pkg-name>[=version]
to fetch and extract a source package, given its name (and optionally,
its version).

But is there any equivalent for binary packages? I.e., is there a tool
that downloads a binary package, given the package's name (and
optionally its version)?

Thanks, Malte