Free London Underground Map for your Filofax

I know you can buy these maps ready-made for your Filofax, but:

1. The map actually changes fairly often, with stations closing and reopening; staying current would cost a fortune; and
2. London Underground hand out lovely ones for free at every station. 

Here is one of the free ones I picked up today:

It's smaller than Filofax Personal paper and it folds out beautifully:

You don't want to punch holes in that. And if you did, it wouldn't open properly. You could put it in a pocket or clear envelope, I suppose, but here's a better idea: recycle some packaging. Here is something I bought that's sealed in unnecessary plastic:

The back of the package is a little flat sheet of transparent, firm plastic. Using a craft knife, I liberated it, trimmed it and punched it so as to end up with a sort of shorter 'today' marker:

Then, it's just a matter of using glue to attach the map. I used a clear-drying glue so you can even see the content where the join is:

 
Here it is, stowed away in my Filo:

And here it is, unfurled and in action:

This trick is fantastic for all sorts of little maps and booklets that fold out. What other ones can you think of?