AutoPager is a Firefox extension which automatically loads the next page of a site inline when you reach the end of the current page for infinite scrolling of content. There are several presets built into AutoPager, you just have to decide which to turn on. I'm primarily using it with Google and on a stock image site. This is one of the recommended addons for Firefox users which can be downloaded from here.

Administrivia: The amount of spam comments submitted to this site overwhelms the legitimate questions asked (Note: not all legitimate comments are made public). They are being submitted by spam robots - the titles and names of the posters usually make no sense. The standard practise is to select all and delete, so real comments are often caught up in the pages and pages of fake comment. We are investigating a good spam plugin to add onto the site to cut down on the amount received.