[STAThread]
    static void Main()
    { // example code only... doesn't do cleanup
        Application.EnableVisualStyles();
        Button btn = new Button();
        Form form = new Form();
        form.Controls.Add(btn);
        ToolTip ttip = new ToolTip();
        ttip.SetToolTip(btn, "Hello world");
        Application.Run(form);
    }

form.Shown += delegate {
    ttip.Show("hi", form, 0,0, 3000);
};