Latex Tips and Tricks

Some latex things that may be helpful for other people (but are mostly here so I can find them).

Single Author with Multiple Affiliations

This has been tested with the ACM sig-alt-release2 documentclass. YMMV with others. Insert the following into the preamble:
For clarity, it is helpful to define commands for the different reference symbols. For example:
Now in the body, authors and affiliations can be defined as follows:
  \alignauthor \ Daniel A.~Lazewatsky\wu\\
  \alignauthor \ William D.~Smart\wu\wg\\
    \affaddr{{\wu}Washington University{\ }} & & \affaddr{{\wg}Willow Garage{\ }} \\
    \affaddr{One Brookings Drive}            & & \affaddr{68 Willow Road} \\
    \affaddr{St.~Louis, MO 63130}            & & \affaddr{Menlo Park, CA 94025} \\
    \affaddr{United States}                  & & \affaddr{United States} \\

How the heck do I typeset a tilde?

Depends what you're trying to do.

The publisher changed up the template on me and now my paper is too long!

Section headings take up a ridiculous amount of room, especially in ACM templates. Try getting rid of subsection headings if possible. You can also reduce the amount of whitespace around elements using the titlesec package.
You can squeeze heading whitespace as follows (in the preamble):
If Latex now complains about commands not existing, that's probably because your documentclass doesn't define something that titlesec is trying to modify. If, for example, it complains that \subparagraph doesn't exist, simply add a dummy command:

There's a symbol I want to use, but I don't know what it's called

Detexify lets you draw symbols and tells you what the corresponding latex command is.