We often are in the condition in which we are looking out for the ways by which we can prevent WordPress stylesheet from being cached. To help you out with the same, the following snippet below will let you achieve the same.
<link rel="stylesheet" href="<?php $theme_data = get_theme_data(TEMPLATEPATH . '/style.css'); bloginfo('stylesheet_url'); echo '?' . $theme_data['Version']; ?>" type="text/css" media="screen, projection" />
Snippet Source/Credit: WPRecipes.com