Catechism of the Catholic Church - online

I have just discovered (thanks to a tweet by Diane Korzeniewski @TeDeumBlog) the online Catechism   of the Catholic Church.

It is fully searchable, the cross-references are hotlinks, the footnote numbers are links which bring up a pop-up box giving the reference...

All  in all this is a fantastic online resource, and should be bookmarked by every Catholic who has internet access.