In a slightly meta fashion the first post is about how to use Latex in blogs on Blogspot/Blogger. I got the answer from http://tex.stackexchange.com/questions/13865/how-to-use-latex-on-blogspot
Here's the key part: just copy this script into the raw template html for your blog (go to template designer and ignore the warnings to edit the raw html, you can put it just after the </head> closing tag and before the <body> opening tag)
<script type="text/javascript" src="http://cdn.mathjax.org/mathjax/latest/MathJax.js">
MathJax.Hub.Config({ extensions: ["tex2jax.js","TeX/AMSmath.js","TeX/AMSsymbols.js"], jax: ["input/TeX", "output/HTML-CSS"], tex2jax: { inlineMath: [ ['$','$'], ["\\(","\\)"] ], displayMath: [ ['$$','$$'], ["\\[","\\]"] ],}, "HTML-CSS": { availableFonts: ["TeX"] } });</script>Just to prove it works, you can do inline stuff $\Pi_{i,j}^{\alpha}f(x,y,z)^3$ as well as display style stuff, $$\Pi_{i,j}^{\alpha}f(x,y,z)^3,$$ by using single and double dollars respectively.
