A simple key ring will do the trick!! For me, I use a wand for 3 reasons:
1. - Leverage! The extra length that the wand has, adds to my overall arm length!! This works really well with heavier gliders!! I find that I don't have to work as hard to keep it moving!!
2. - Eyesight!! My eyes aren't good enough to ever find the line if I ever dropped it!! So this method of using a wand helps me keep track of the line at all times!! It's always in my hands with that key ring on a finger!! I do use preset lengths of line for all but 1 glider, so far!
3. - Flex! I've managed to find wands that work with my kites, not against them! So far, every kite seems to behave differently from one another!! Each, IMHO, needs or uses a different wand to get the most out of them!!
I've seen many that don't need or want them, that's their choice!! But with my situation, using them works extremely well to make things as easy as possible and to enjoy gliding!!