Example: Formatted todonotes

\documentclass[a4paper]{article}

\usepackage[english]{babel}
\usepackage[utf8x]{inputenc}
\usepackage[colorinlistoftodos]{todonotes}

\title{Example: Formatted todonotes}
\author{You}

\begin{document}
\maketitle

\todo[inline]{Here's an inline comment below the title \& author.}

\begin{abstract}
Your abstract.\todo{You can use \textit{italic in a comment}, like this.}
\end{abstract}

\section{Introduction}

Here is some introductory text.\todo{You can use \textbf{bold in a comment}, like this.}

\end{document}