ASCIIMathML is a great package by Peter Jipsen for including equations in web pages. It works great with WordPress.

I simply added

<script type="text/javascript" src="/~gb/ASCIIMathML.js"></script>

to my Header.php.

Update: I made a plugin to conditionally insert the code above into pages that contain grave accents.

Here is an example. I wrote \` e^(i pi) = -1 \` and it produces ` e^(i pi) = -1 `.

I modified Peter's script to disable the $ as a delimiter since I tend to use those in other contexts.