Take complete control of text formatting options on your blog: Formatting and encoding per post, globally on posts, and globally on comments.

Text Control will allow you to choose from a variety of formatting syntaxes and encoding options. You can choose between Markdown, Textile 1, Textile 2, nl2br, WPautop, and “No Formatting” for formatting along with the choice of SmartyPants, WPTexturize or “No Encoding” for character encodings.

TextControl – WordPress Plugin Repository – Trac.