Post Centering? Options

[KrissyKat]

I'd like to know if theres a script that defaults all the text in your posts so that its centered [theres the option for it in the modules, but not the actual posts unless you have premium]. I know if you do edit html in the post, you can edit it so the text is centered, but I was wondering if there was one where you didnt have to edit every single one, so that it was the default?

-Krissy Kat