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.

...is open source. I downloaded and now use a private copy to collect all of my ideas

This would allow a person to track how other people in 43 things are doing with a particular shared goal. For example, If I find that “Gorble” seems to be making great headway with exercising, I would subscribe to their EXERCISING GOAL. I would then get an Email every time they made an entry (not anytime someone made a comment).