Create an IIS binding using the MS ServerManager (Microsoft.Web.Administration namespace)

sitecreator.cs

/// <summary>
/// Create an IIS binding. Warning: Sitecore will pickup the IIS
/// change and will restart when this code is executed!
/// </summary>
/// <returns></returns>
public void CreateIISBinding()
{
  ServerManager iisManager = new ServerManager();
  Site site = iisManager.Sites[Properties.Settings.Default.IISInstanceName];
  string binding = string.Format(@"{0}:{1}:{2}", "*", "80", this.HostName);

  Binding siteBinding = site.Bindings.Where(x => x.BindingInformation == binding).FirstOrDefault();
  if (siteBinding != null)
  {
    throw new InvalidOperationException("IIS Binding already exists");
  }

  site.Bindings.Add(binding, "http");
  iisManager.CommitChanges();
  this.IsIISbindingSet = true;
}