The idea you haven't told anyone about

Five months ago I had an idea for XEdge and didn't tell anyone for weeks.
Not because it was bad. Because saying it out loud made it real, and real meant I'd have to actually try.
I think a lot of people are sitting on something like that right now. Not lacking ideas — lacking the nudge to say it out loud to someone who won't laugh.
So here's an open question: what's the idea you haven't told anyone about? Drop it in the comments, here or anywhere else you've seen this question today.
No pitch coming. Just genuinely curious what's out there.