I seem to have managed over the last few years to be double booked for WPPD. I had great plans, but in the end it was a homebrew body-cap on my DSLR that took a quick tour around the garden before I had to dash out for the day.
The body cap has a triangular pinhole made from the black backing paper of an old 120 roll film. The pinhole area combined with the DSLR focal length gives approximately f/152.
The dog's chew toy came out best as it has good saturated colours and an entertaining structure. The biggest problem I find with a pinhole on a DSLR however is it really shows up every speck of dust on the sensor