I saw some funny videos made at work this week:
A few summer interns decided to say goodbye by creating a music video (the waterfall and rock garden are right outside my building too!). I hope they code better than they sing. ;-)
The Virtual Earth team made a funny film on the creation of Virtual Earth. Corny, but fun to watch in a room full of hundreds of geeks chowing down on Krispy Kremes and coffee.
There was also a third video on punishing our developers for their bugs by driving sharp metal objects into their ***es, but I don't think it's been posted publicly yet and some group like legal or PR would probably have a field day with it. ;-)