I almost couldn't believe this when I heard about it, but it was true! Andre Agassi and Roger Federer playing tennis on the helipad of the Hotel Burj Al Arab in Dubai.
Check it out http://www.burj-al-arab.com/tennis/
(I've got more photos in a powerpoint slideshow - don't know exaclty where they came from, but they were emailed to me. Let me know if you want to see more!)