Auto-flowing Blocks in Beamer/BeamerPoster environment?

Question

What I have: Multi-column beamerposter with blocks in each column

\begin{columns}
    \begin{column}
        \begin{block}{A Block}
            ...
        \end{block}
        \begin{block}{A Block}
            ...
        \end{block}
    \end{column}
    \begin{column}
        \begin{block}{A Block}
            ...
        \end{block}
        \begin{block}{A Block}
            ...
        \end{block}
    \end{column}
\end{columns}

What I would like to do:

\begin{columns}{2}
    \begin{block}{A Block}
        ...
    \end{block}
    \begin{block}{A Block}
        ...
    \end{block}
    \begin{block}{A Block}
        ...
    \end{block}
    \begin{block}{A Block}
        ...
    \end{block}
\end{columns}

Basically what I'm trying to head towards is a beamerposter template that will let me easily switch between portrait and landscape views for instance by setting the columns to 2 (as above) in the portrait version and to 3 in the landscape, with blocks being arranged in order top to bottom as they fit.

Any ideas?