An anecdote
I was reading a paper on Socio-Technical Capital a short while ago, which discussed a semi-public transport system where people wait around in certain locations and drivers give them a lift so that they can use the special lanes for higher occupancy vehicles to get to work faster overall - everyone wins. Sometimes it doesn't work out perfectly though; "the driver didn't go to the promised destination, drove in an unsafe manner, or left something on the seat that soiled the rider's clothes". This reminded me of last night, as 3 of us from the cricket were picked up and had to quickly pile into the back seat of the car at a red light.

From the front seat: "Just watch out for the avocado"
A few moments later, from the back seat: "What am I sitting in?"

Yeah.

Poor Nathan fossicked around and held up the mangled remains of part of an avocado for the remainder of the trip. Of course, it was funnier for me than everyone else, as of the other four people:
One owned the car up to and including the avocado smeared seat...
one had an on-loan-from-supervisor pre-print textbook sitting underneath the avocado...
one owned the unfortunate avocado itself...
and one was the poor guy who actually had to sit in the ad hoc guacamole for some time.