I have many many rulers, I counted over 20 at home (I use to be a patternmaker) and I have taken alot to work so keeping them organized is both important and not an easy feat.
I found the wonderful ruler holder in the quilting section of Joanns but it looks easy enough for a creative husband to make if he is so inclined.
(You can also see a Sharpie marker attached to the holder. I use velcro to attach pens and makers so I always have them handy. It's just remembering to put them back that gets me in trouble but I am getting better about it and it helps to have them throughout my design room)
Once you have one of these and can grab the ruler you need easily, you will wonder how you did without it!