Hey Y'all,
So after lurking for sometime and taking in all the great tips I think I actually have one to offer. I just came back from visiting family in Mexico. I decided to keep what I had on my person to a minimum. I was not lugging around a backpack visiting all the Mayan ruins and beaches. I carried only what I could fit in my travel security belt and my pockets (and not look like a chipmunk). This left me to carry my water bottle and towel in hand.
After my first attempt to take a photo while trying to juggle the towel, map, water bottle, and the camera I decided there had to be a better way. I usually carry about 7 ft. of 550 cord wrapped around one of those key-ring carabiners you find at the checkout counter. I made a quick sling by tying each end of the cord to the rolled up towel and clipping the carabiner to the water bottle. Free hands, it was perfect! It also came in handy as a laundry line to hang my wet towel to air dry and as a pants/underwear suspender in public men's restrooms where you *don't really* want your pants/underwear to touch the floor or side of the toilet.
I think it's a great way to carry the cord, have it readily available, and not get it tangled. I don't know what the knot is called but it's the one where you pull on one end and it starts to come undone. I don't know if someone else has already done/posted this but I sure do find it handy! Here are a few pics.
The knot:

Completed:

Towel sling: