Another conversion for 4chan, /b/ackwash, which shows quoted posts in a small hovering window next to the quote link when moving the mouse over it.
Screenshot

Download
4chan Backwash for Opera, Version 1.2c
Installation instructions
See installation instructions here.
Changelog
01/22/2009 – Version 1.0a. Tested and working with Opera 9.6. Fixed a serious bug with scrolling to the wrong position when clicking a quote.
01/23/2009 – Version 1.1. Now works with fychan by sneakily re-attaching event listeners when the document was modified.
01/27/2009 – Version 1.2. Now also shows quotes pointing to the thread starter.
01/28/2009 – Version 1.2a. Somewhat fixed quirky display for posts quoting the thread starter.
02/01/2009 – Version 1.2b. Minor changes to prevent functions and variables from leaking outside of Backwash’s namespace.
01/09/2010 – Version 1.2c. Should work for the new URL layout now.
Tags: 4chan, backwash, opera, userscript
Doesn’t seem to work with fychan anymore.
Disregard that, I suck cocks.
Thanks
No more .zip server. May I request a fix?
I tried to fix it myself, but this is no simple find and replace job. It seems that it doesn’t matter if 4chan was using .zip or not.
I don’t know if it helps but it was after the server change when scripts like this or the filter stopped to work.
This breaks autosizer.js, so I disabled it on images.4chan.org.
I slighly adapted the script to 4chan’s new URL layout. I apologize to those who posted fixes here in the comments, apparently my spam filter ate most of the solutions.