The new discussion system rendered this script obsolete, but it remains here for reference.
This script was intended to make reading of Slashdot discussions more convenient. It inserted buttons to expand and collapse any comments and comment threads on a page. Comments not on the original page were loaded from the server.
slashdot_expandable_comment_tree.user.js (21.97 KB; 2006-06-10)
slashdot_expandable_comment_tree-sans_xpath.user.js (24.63 KB; 2006-06-10)
See the top of the script for more information.
This script is also hosted over at Userscripts.org