Creating a profile gives you greater control over what people find when they search for your name on Google. Your profile can include online photos, links to your blog or other online profiles, and ways for people to contact you — and you can restrict contact information like your address and phone number to only the people and groups you choose.
If you want people to be able to contact you, but don't want to reveal your email address to the world, you can hide your username and use a 24 digit number instead. Turn on the 'Send a message' feature, and anyone with a Google Account can send you a message through your profile, without having your email address revealed to them.
Don't have a profile? Go to www.google.com/profiles to get started.