Keep a log of my ideas

I use two methods for this:
1) Adding a Someday/Maybe Category for tasks in MS Outlook. Whenever I get ideas, from the sublime to the insane, I put them down and store them here. I occasionally review the list (and move some things to the “Likely Never” category!)
2) Tablet PC, Tablet PC, Tablet PC. Its the best darn computer improvement in the last decade. I can put handwriten notes and ideas immediately into MS OneNote, and even attach To Do flags of various kinds or search my handwriting.