12 May 2007
Sinterklaas
Rather than having Santa Claus show up for Christmas, in Holland the tradition involves a similar looking guy called Sinterklaas who, on December 5th, also goes from house to house to deliver presents.
Several years in a row I would invite Sinterklaas to Vancouver a few weeks earlier to bring some gifts for my friends. In 2007, the evening got inspired by this XKCD comic…

I first ordered 500 plain balls, as a test. Satisfied, this lead to an invitation video…
I then ordered 4000 more colored balls, resulting in a bedroom sized ballpit for the actual event.
My friends and I enjoyed the ballpit for about two months, after which the entire collection of balls was donated to a local home for children with developmental disabilities.