I carry mine in my pool bag. I roll it up in a piece of transparency paper and then put a rubber band around it. Never lose and always have it when needed. It does have a small bend to it. Does not affect play. But I will roll it up the other way the next time. Never have a problem with it.
Yup, I used to roll mine around the butt of my jump cue - I take a set of balls with me when I go to play now, so it fits easily in the case for them.
I found if you only keep it rolled when you're out with it, and then leave it flat inside of a large textbook or something at home, it held its shape almost perfectly.
The tables where I play are so full of divots that the magic rack makes things a LOT easier. It's a must, in my opinion.