What is the coolest Groovy integration sample ever?

Hi XWiki lovers, I need to prepare a demo of XWiki and Groovy for next week (For Sun Tech Days in Paris) and I'd like to show some cool Groovy integration in XWiki (something visual like Flickr + Googlemaps integration in a Wiki page). I'm hoping that some of you have something cool that I could reuse for a demo (with full attribution of course. I can even cite the author's name during the demo!). So who has the coolest Groovy integration example ever? :) Thanks -Vincent