Allow customers to change qty of items listed on each page

I have had a couple of customers complaining that the default amount of items displayed (24/page) is too small, and they're weary of scrolling through multiple pages. I understand that 24 is a nice default, but it would be great to be able to have the end user choose if they want a quicker load time with less items, or longer load with more items/page, rather than being just stuck with one option.