I have up to four lists per task (tasks themselves form a hierarchy):

- todos: for the immediate future

- goals: for longer term objectives

- ideas: for spontaneous 'eureka' moments

- gotos: related bookmarks and local folders

Whenever I'm done with an item, it goes from the list into the task timeline where I journal all other progress.

I manage them all with a tool I wrote myself, called tau (shameless plug, http://signup.tau.la)