This is an overview of a nice way to include LaTeX equations as PDF's in something like a powerpoint presentation. Note: this is based on the reverse engineering of the program LaTeX Equation Editor for Mac OS X. I use this program regularly but since the equivalent isn't available for windows or linux (in such a nice package), I decided to post some instructions.
First off, you'll need to write up a small .tex file that has something like the following in it:
\documentclass{article}
\pagestyle{empty}
\usepackage[dvips]{color}
\color[rgb]{0.000,0.000,0.000}
\begin{document}
\[\int^\infty_{-\infty}\sin \theta d\theta\]
\end{document}
where you should notice the line that starts with \[ and ends with \] is the equation of interest. Call this tex file equation.tex or something more meaningful to you. The next step is to simply run latex on this file, that will generate a file called equation.dvi.
latex equation.tex
To get the DVI file into a nice eps with just the equation in it we'll use some extra flags for the dvips command:
dvips -E -Ppdf -x 3600 equation.dvi -o equation.eps
Where -E says "make this an EPS with a tight bounding box" (tight in the sense of no extra paper not MTV Pimp-my-ride tight), -Ppdf means we'll be making a pdf later so do the right thing with the fonts, and -x 3600 magnifies the fonts to make a nice looking eps file. Finally the last step is to convert the EPS file into a PDF file (unless your software is ok with EPS in which case you are done).
epstopdf equation.eps
... and that's that.
In summary the following steps serve as a guide, be sure to make your LaTeX code look like the example above but with your equation in between \[ and \].
latex equation.tex dvips -E -Ppdf -x 3600 equation.dvi -o equation.eps epstopdf equation.eps
For a sanity check, you may want to run this process on the code I've written above. If you do all the steps correctly, you should get a pdf that looks like this