My older daughter asked what I'd like for Christmas.
On TRF, MyGypsy posted a link to the INCRA Rulers video CLICK HERE
This is one of those tools that could be invaluable.
The inset picture shows the small holes and slots that fit a .5 MM (fine) mechanical pencil. Instead of marking over the edge of a standard ruler, your pencil point goes into the holes and slots for more accurate marking!