I like using a directed acyclic graph, presented as an outline. E.g., Leo: http://webpages.charter.net/edreamleo/front.html http://webpages.charter.net/edreaml

I like using a directed acyclic graph, presented as an outline. E.g., Leo: http://webpages.charter.net/edreamleo/front.html http://webpages.charter.net/edreamleo/front.html