Can I use LaTeX in my wikis?

Yes, the syntax is :

$latex formula$

For example :

$latex \left( \frac{a+b}{c-d} \right)$ 

Will give :

$latex \left( \frac{a+b}{c-d} \right)$

The rendering is done on the client browser using the MathJax Open Source library.

This works on every browser without a special plugin.