This is, by far, my favorite method of collaborative drawing!
The (actual) name of this project is a bit dark....Its called an Exquisite Corpse..(cue lighting strike and 'dun dun DUN!' sound byte)..perfect timing as this is October and Halloween time and all!
This collaborative drawing... "is a method by which a collection of words or images is collectively assembled. Each collaborator adds to a composition in sequence, either by following a rule (e.g. "The adjective noun adverb verb the adjective noun") or by being allowed to see the end of what the previous person contributed." (Wikipedia).
Fold your paper accordion style. Start the drawing in the first box, leaving little 'hints' (lines) running over into the next box..Oh whats that? What are you drawing? Anything goes! (within reason)--the more random it is, the better the drawing is in the end. You can easily turn this into a feelings directive though (i.e. draw one box happy, one mad, etc).
Fold it over the paper (to hide your drawing) before you pass it on. The next person should only be able to see the portions you drew over the line, which they will connect to their drawing.
I've used this activity when getting to know a client, as its a great ice breaker (the drawings can get pretty silly). Or if have a client who you are having a hard time connecting with, this is an easy way to get them talking while they are busy with something else. It can also be used to begin the conversation of cooperation skills (this IS a collaborative drawing). OR you could use it to start education on how you can't always judge a book by its cover (i.e. you only get to see a little bit of the other drawing and don't get to see the full picture until the end).
Go forth and be creative my friends!