[cpeterso]

Instead of hiding the project until completion, you could (after a little covert research) share the idea with the boss and time box the development: if the first increment of X days or a week continues to look promising, then attempt the next increment as long as the boss still has an appetite for your idea.

[MobiusHorizons]

never underestimate how little appetite management (or anyone really) can have for good ideas when they are stressed (eg a time crunch).

[datadrivenangel]

Do this after you've built it.