GTD is a philosophy connected to David(?) Allen and stands for "Getting things done". The imho most important ideas from gtd all require tagging:
- you dont have to have full-blown project plans for all your personal projects. make a list of projects and one of "next steps". use case: tag tasks as "next".
- every task has tags about its context, which in gtd sense means: in which location or which state of mind do i do this. use case: tag tasks as "at home", "at the next meeting", "think about", "phone", "webresearch",...
- "waiting" tasks have a kind of timeout (eg when i wait for a reply but it wont come)
- write down tasks that are not decided but tag them as "perhaps/someday"
- do a clear separation between wiki and task space