Today is May 1st, and I made a "demotivational"-style poster for the occasion.
The LaTeX code (see below) can be easily modified for other posters of this
style.
% "Demotivational" poster template in LaTeX
\documentclass[12 pt,portrait]{article}
\usepackage{fullpage}
\usepackage{url}
\usepackage[pdftex]{graphicx}
\usepackage{color}
\definecolor{white}