Just wanted to list different ways to express your product backlog:
Effect mapping: http://gojko.net/2011/09/23/effect-mapping-in-practice/
(Mind map starting from Who, Why, What, How)
User story mapping: http://www.slideshare.net/nashjain/user-story-mapping
(Visual map with timeline and priorities)
Tree map: http://en.wikipedia.org/wiki/Treemapping
(You have to see it to understand – I can’t really explain… more useful for visual reporting)
Release driven user story mapping: here
Idea wheel: I need to find out what it is.
I will add some more in this blog soon!