Keeping goals/ projects to yourself is a good idea until you're in the final stretches. At least, if the project is big enough to have final stages.

I'm working on a game currently and for the first few months of development, I'd occasionally mention that i was working on something but not the specifics of it until I was ready with a board prototype for playtesting. My friends loved it and I'm sharing screenshots of my progress on the web version.

Having their feedback has been invaluable to finalizing the design and even the little things ("they 'like' this pic! yay!") keeps me slugging through the 2.5k lines of JavaScript that make up the game client.