You don't need to, actually. It's one of the few unwalled gardens left on the Internet :). You can ask questions, post answers, and even propose edits to other people's posts without having an account.
Edit: to clarify, I would have answered your question if I knew. I don't, but I think those sites give good answers.
Edit: to clarify, I would have answered your question if I knew. I don't, but I think those sites give good answers.