It's convienent to auto-populate the "your name" and "your email address" fields if a user is logged in because the site already has the information. I added the following lines to ContactForm.ascx.cs at line 89:

            SiteUser siteUser = SiteUtils.GetCurrentSiteUser();
            if (siteUser != null)
            {
                this.txtEmail.Text = siteUser.Email;
                this.txtName.Text = siteUser.Name;
            }   

-Jesse