Author: James Allen (January 2012)
Whenever I'm writing long LaTeX documents I always find myself jumping backwards and forwards in the code trying to remember what I named a \label. To save me losing my place in the code I use the showlabels package which displays the name of the label next to the corresponding equation. Then I can look in the PDF where it's easier the find the equation I'm looking for and I don't need to jump around in my code. It works on nearly everything you can assign a \label to. Marvellous!
Usage
In your preamble put:
\usepackage{showlabels}
Example output
Options
You can provide an option to showlabels to tell it where to place the labels:
\usepackage[inline]{showlabels}
Available options are (taken from the documentation):
outer [default]—all notes are placed in the text's outer margin
inner—inner margin
left—left margin
right—right margin
marginal [default]—put notes in the margin
inline—put notes inline, as much as possible, and ignore any of the margin-placement options above
nolabel—do not insert a marginal note for \label commands
draft [default]—does nothing, partner of...
final—turns off all the package's functionality
Note that showlabels should be included after the packages amsmath and hyperref to work correctly with them. See the official documentation (PDF) for more details.