For those service oriented businesses that want this to default to the first item listed as a service you can change: Smarty/templates/inventory/ProductDetails.tpl
Search on "Following code is added for form the first row"
Find the reference to title="Products" and change to title="Services", "products.gif and change to services.gif,
onclick="productPickList" and change to onclick="servicePickList"
*Works with vtiger 5.4
Thanks to timcampbell