What's the idea ?
All entrepreneurs already have their ideas.. you don't need to hide yours.. you just need to be faster than anyone at implementing it.
I think it would be better for you to get a reality check by sharing your idea and having people comment on it. You could get constructive feedback from that.
Also, anything related to Bitcoin will most probably not be a "web site", but rather a web app.. and probably more involved than you think.
So, shell it out.. what is it ?