Sometimes in pubs I used to spend time folding empty crisp packets into shapes (don't judge me!), so I can see how Tube map folding could become rather addictive. Perhaps it will take on & we'll see people folding maps with the same intensity as being invovled in a Sudoku puzzle.
Matt has moved on from one map to using a number of maps, which you can see on his blog. He is also spreading the joy by leaving the folded creations on the map holder at the end of his journey
"Each time I take the Tube, I am
going to fold a tetrahedron from two maps and leave it on the maps when I
leave the tube. I started this yesterday, leaving a tetrahedron on the
maps at South Harrow. In the evening, it was still there. How often do you think I will return to find a tetrahedron still there? I
will be keeping a tetrahedron diary so we can find out the answer to
these most important questions...: