Paperbaby just sent us a beautifully colourful postcard. Here it is for you to enjoy. Please, write him back!

Credits and source attribution
Credit: Brian Sears
http://users.tru.eastlink.ca/~brsears/math/oldprob.htm#s32
Thanks to Dave Pritchard for bringing it to our attention:
http://mathoverflow.net/questions/8846/proofs-without-words