Categories: Products per page options

There is no option to select how many products are being viewed other than the setting in admin,

can't the end user have to option to pick whether they want 10, 30 or 100 products to view at a time

Would also be nice to have this option changeable on templates
(i.e use a different template for a view all category and set it in the template to view 100 products, another template i want to show 32 products etc..)