In this instructable, I'll walk you through the process of
- building a cat sensor out of a simple momentary switch, foam core and foam strips
- reading the cat sensor on your Mac or PC using Arduino and Processing
- automatically posting status updates to Twitter when your cat takes a nap or wakes back up
- taking pictures of your cat on the bed with a webcam and uploading the pictures to a webserver
This instructable is inspired by Tom Igoe's Networked Cat Project in the book "Making Things Talk"