Ext JS 4's brand new grid supports infinite scrolling, which enables you to load any number of records into a grid without paging.
The new grid uses a virtualized scrolling system to handle potentially infinite data sets without any impact on client side performance.
The code is not minified, see infinite-scroll.js
As the edge of the rendered data scrolls towards being in view, the table is refreshed, and repositioned to maintain visual scroll position.