Actually, you can use any type of edible leaves, as long as they are big enough to handle--clean them first, of course. Before you coat them with chocolate, though, you need to remember two keys to success for making chocolate leaves. First, only add chocolate to the backs of the leaves, not the tops. Secondly, you MUST grease the leaves lightly with shortening or cooking spray so that the chocolate will peel off easily. Peel the leaves off of the chocolate, rather than vice versa.
Very cool indeed!