Infinite scrolling plugins do waaaay too much, especially if you’re already using Backbone.js. Seriously, look at the configuration options for Paul Irish’s plugin (one of the most popular infinite scroll libs).
I wrote a simple plugin that notifies you when you’ve scrolled to the bottom of a particular dom element. It’s called jQuery.bum-smack: for when you hit the bottom… of a dom element while scrolling.
Read more about the motivation on the project’s github page: https://github.com/mrjoelkemp/jquery.bum-smack
It gets to the core of what you need when you’re using backbone collections with a list view that handles rendering. Does the infinite scroll plugin really need to take care of your fetching and rendering at that point? Nope.
Hope it helps!