I'm facing this question, too, after updating from 6.5. I had several mods in place that did things on the showflat and showthreaded based on a user's groups, such as custom group icons and so on. In 6.5 I used this kind of code:
PHP Code
// Figure out what to display based on their groups
	if (preg_match("/-5-/",$postergroup))  { // adjust this group number if needed
			   $postrow[$i]['GroupName'] = "Premium";
			$postrow[$i]['GroupPic'] = "<a href=\"http://www.hairtell.com/ubbthreads/premium.php\"><img src=\"http://www.hairtell.com/ubbthreads/images/subscriber01.jpg\" border=\"0\"></a>";
	}
But I hardly know where to begin in the new 7 code. Any thoughts or starters?
Are there any pages in particular that load a user's group and display something based on it, so that I can examine that code?
Thank you!