Here is a Twitter campaign from Bonafont bottled water in Brazil:
Mini-fridges filled with Bonafont bottled water were sent to influential Tweeters. Using a light sensor, timer and a lot of gadgety stuff, this tweeting fridge posted tweets.
The first time the fridge is opened the @InfluentialTweeter gets a tweet:
Hello @InfluentialTweeter!!! I'm in your fridge. Let's share with the world the experience we have together. Go to http://www.bonafont.com.br and allow me.
Then every time the fridge is opened another tweet is posted on @InfluentialTweeter's timeline with tweets like:
There were a variety of different messages, including messages to remind @InfluentialTweeter by DM to drink water when the fridge has not been opened in a while.