LaTeX - underline text (font) in a LaTeX document

LaTeX font question: How do I underline text in a LaTeX document?

This actually ends up being one of the easiest things to accomplish related to LaTeX font formatting. Its a little inconsistent from the LaTeX tags you use to create bold and italicized text, all you have to do is use the LaTeX \underline tag:

\underline{Text you want underlined goes here.}

Note that the \emph{} tag can produce the same underlining results. The LaTeX book I was just looking at says that this is "usually" the case. I haven't tested this yet, though.