My current solution is something along these lines:
\begin{document}
\begin{multicols*}{4}
% ===== First TWO columns of content =====
\lipsum[1-5]
\columnbreak
\lipsum[1-5]
\columnbreak
% ===== End of my first two columasn =====
% Fill the third column, which I want blank:
\vfill\null
\columnbreak
% include graphics in minipage, set the anchor to top, then use \raggedleft
% to produce an image at the bottom-right of my last column / the page:
\vspace*{\fill}
\begin{minipage}[t]{\columnwidth}
\raggedleft
\includegraphics[width=40px]{{myImg.png}}
\end{minipage}
\end{multicols*}
\end{document}
As I write in the code's comments, I use a combination of what is mentioned on this and similar posts, where I use \vfill\null and \columnbreak to produce an empty column. Then, in the final column, in my situation, I am interested in an image at the bottom of the column, seated on the right side (it looks as though it sits on the bottom right corner of the page). Thus I use the combination of \vspace*{\fill} to fill the column's vertical space and a minipage anchored with t to place the image without being cut off the bottom of the page. Within the minipage I use \raggedleft to get the horizontal alignment I desire.
Please note that, in the following image, the layout of my page (e.g. is horizontal) is due to this being in the mid of an active project of mine.

flowframcan be of help here. See Three-columns text with figures of 2\columnwidthand How to write a title/abstract spanning 2 columns in 3-column page using multicol?. – Werner Dec 29 '12 at 18:09multicoltotwocolumn" a valid answer? – yo' Jan 05 '13 at 14:40\raggedbottom\enlargethispage{-0.2\textheight}, where you modify0.2to a value such that the output looks nice. The only real drawback of this method is when you have chapters because then you must do it for each chapter. But who has a twocolumn document with chapters? – yo' Jan 05 '13 at 18:29