My Projects, Next Actions and Someday/Maybes are all entered in Tasks (aka To Do on earlier Palms), with each list assigned to its own category (e.g. @computer). Checklists and reference material (e.g. Focus Areas, Reference, Thoughts) go into Memos, each with its own category except for ad hoc lists which go into my category called "Lists." Date specific, hard landscape items go into the Calendar.