On this topic, is there a good place to ask "does this exist?" where you'll get good answers. Like, when I'm about to start hacking on something, I'll Google around a little, but sometimes I find out after I start/finish that it already exists in a reasonably-good form. An Ask HN thread every once in awhile I guess would be ok, but it seems like overkill in many cases, especially if not many people would really be interested in the answer.

I guess ideal would be a piece of HN just for that that doesn't end up on the homepage, but some people would look over them once a day or so and see if they do know of something that exists.