you can for example use
<%if post_is_poll%><b>Poll: </b><%endif%>
just before <%post_subject%> on forum_view.html to make polls stand out more (so that it looks exactly like phpbb). With the graphic too, you could just make your own graphic for polls (poll with replies, polls which are hot) and put it into <%if post_is_poll%> .... <%endif%> tags.
I hope that helps. If you come up with some nice graphics, let me know.
Iyengar Yoga Resources / GT Plugins