WCF and unit of work scope

What is the recommended practice of scoping the unit of work within WCF? I know that I could use the per request unit of work scope if I enable ASP.NET compadability, but what if I am hosting in IIS7 using TCP?

I ended up writing this. I have done some basic testing and it seems to work. I thought you might be interested in including it in LightSpeed for other WCF users.

public class WcfUnitOfWorkScope<TUnitOfWork> : UnitOfWorkScopeBase<TUnitOfWork> where TUnitOfWork : class, IUnitOfWork, new()
{
  private class UnitOfWorkScopeExtension : IExtension<OperationContext>
  {
    public TUnitOfWork UnitOfWork { get; private set; }

    public UnitOfWorkScopeExtension(TUnitOfWork unitOfWork)
    {
      if (unitOfWork == null)
        throw new ArgumentNullException("unitOfWork");

      UnitOfWork = unitOfWork;
    }

    void IExtension<OperationContext>.Attach(OperationContext owner)
    {
    }

    void IExtension<OperationContext>.Detach(OperationContext owner)
    {
    }
  }

  public WcfUnitOfWorkScope(LightSpeedContext<TUnitOfWork> lightSpeedContext)
    : base(lightSpeedContext)
  {
  }
 
  public override TUnitOfWork Current
  {
    get
    {
      if (OperationContext.Current == null)
        return null;

      UnitOfWorkScopeExtension extension = OperationContext.Current.Extensions.Find<UnitOfWorkScopeExtension>();
      if (extension == null)
      {
        extension = new UnitOfWorkScopeExtension(LightSpeedContext.CreateUnitOfWork());
        OperationContext.Current.Extensions.Add(extension);
        OperationContext.Current.OperationCompleted += OperationCompleted;
      }

      return extension.UnitOfWork;
    }
  }

  private void OperationCompleted(object sender, EventArgs e)
  {
    Current.Dispose();
  }

  public override bool HasCurrent
  {
    get { return (OperationContext.Current.Extensions.Find<UnitOfWorkScopeExtension>() != null); }
  }
}