At the moment I am experimenting with the Dynamic HTML Chess Widgets from dhtmlgoodies.com. Maybe it will be possible to use this within this site, but first I’ll have to get this working outside of WordPress. This turns out to be harder than expected, because even the demo files won’t run as expected.
The main problem seems to be that all games in the pgn are collated to one game resulting in a moves like “1-0″ and “undefined”.
Update January 22, 2011
The problems have been solved as you can see in the 1001 brilliant checkmates post.