I sail a small 21' boat with two children. I put netting on the lifelines when I got the boat and now would not own a boat without it. (And yes, we still use lifejackets and tethers)
I got mine from www.marisafe.com
, seemed reasonably priced. I am fairly happy with the netting, however I do not care for the comstruction, there are not real knots in the netting, it is more just woven or something, I do not know exactly how to describe it. It is holding up ok, but where the lifelines open to get onand off the boat I used some little carabiner type clips to close th eeadge of the netting and the joints are starting to come apart there. Everywhere else the netting is holding up OK. We only plan on having the boat for a few years and where woking on a very limited budget so this netting is working out fine for us, but if you want somehting that will last for a long time I would look for something a bit heavier with real knots in the netting. As the saying goes, you get what you pay for.
I was suprised at how many people on the docks had not seen netting like that, and how many people stopped to ask questions about it and compliment it.
After sailing for two summers on a boat with netting, My wife and I chartered a boat in the San Jauns for a week for our tenth anniversary which did not have netting. I kept trying to set things (Boat hook, coffee cup, jacket, etc. ) on the side decks and beside the cockpit and almost lost them overboard! I just got so used to being able to toss things beside the cockpit without worring about it that it was annoying to have to look around for a secure place to put things. I think I would have netting on any boat I owned just for tha reason!