I believe the option to add purchase order tab to the toolbar would be very useful. With the addition of being able to creatre a purchase order from the toolbar it would save a fair amount of time and be very convenient. It would be handy in the sense that it is only one click compared to having to go home and click purhcase orders or going throw the 'window' tab at the top of the page. It would mean there would be a seemless transition between swithcing between invoices and purchase orders.