Ok… I haven’t seen this elsewhere in the forums… but forgive me if this already known.
If you are looking for a method of carrying your yoyo that is a bit more subtle than the belt-loops that are sold on yoyo sites, grenade pouches work perfectly.
Tactical Molle PALS SINGLE Frag Grenade Pouch NIP Carrier Molle Pouches-BLACK
got one off Amazon for less then $8.
I call it my Yoyo Concealed Carry… I think my wife is going to have me committed if I keep this up. LOL 
heeeeey this is pretty cool. The only down side is that if someone recognizes that as a grenade pouch, and then you start pulling something out of it, that person might start freaking out.
“Yo-yo in the hole!!!”
Just don’t bring your yoyos in that through an airport or something.
Drop the yoyo, and turn around. Slowly. No sudden moves.
Department of Homeland Security is currently tracking several lone individuals that seem to be stockpiling yoyos. They meet on an internet forum…
I wouldn’t be surprised if the word “grenade” lit up a light or two at the NSA and we had a couple of techs sniffing around here for a few minutes.
“Welcome to YYE, NSA! We recommend some of the starter sets as a good place to begin your yo-yo journey.”
NSA We love you Air Hug