Actually I need to make an easy and little tweak to this code, but I'm really in trouble. Here is my site http://thisweekin.net/malibu/
With this code I created the rule to show up the category name above the post http://screencast.com/t/vgZUi6UNCw, and set up only for "Events" category to show up the children names instead of parent name. http://pastebin.com/1Y7wyEX0
Actually I'm creating sub-categories not only for "Events", so
I'd like to get Children names for every category (and not only for Events).
If Parent category doesn't have children, it will display the parent name (it already does this job).