i started to modify the fMulti theme found at http://www.fahlstad.se
There are some changes made in the index.php
You might have a look at it, i can´t help you in detail because i´m not a php expert.
The codeline is simply changing the class of the entry div to “entry firstpost” or “entry”.
The trendy image is defined in fMulti style.css . Just look for .firstpost
Backup your existing files and try to paste this codelines into your theme.
