I love when creativity strikes, leading my into a time to brainstorm, project manage, and get things done.  To get those ideas drafted out and implemented, I use a variety of tools.  First, I brainstorm ideas in a mindmap, like MindJet Mindmanager.  Then, I schedule out tasks in Things.  Finally, I review the calendar using BusyCal.  Best of all, all of these things work from my Mac and iPhone.