First, get the Autopagerize script from userscripts.org. Then, add these lines in the SITEINFO section:
pageElement: 'id("alpha-inner")/div[position() > 1 and position() < 22]',
Now look at any journal or friends page. When you scroll to the bottom, the next set of entries should autoload and appear below the ones you're looking at, without having to load the whole next page. Awww yeah.
Inspired by Sekimura's hack for Vox.