That is what Jon Stewart called the BeerNeck and BevNeck.
Think of them as neoprene wet suits that insulate beer, sodas and bottled water and let them hang from your neck or clip to your belt, pocket, pack, purse or what have you.
The BeerNeck, seen left, zips up to keep the beer very cold - Marty can attest to that - and comes with an attached bottle-opener that also reseals the bottle until you require another sip.
The BevNeck, seen right, is the one you want for bottled waters and sodas that have twist on-and-off caps. Instead of a zipper, the BevNeck’s neoprene has a velcro flap with a hole. Put the bottle in the neoprene jacket and pull the flap over the cap to secure it.
The BeerNeck and BevNeck keep your beverage cold, easily accessible and they reduce the potential for spillage, breakage or losing your bottle. Each Neck comes with a detachable neck/shoulder strap with a quick-release connector and a swivel clip attached to the back for clipping to bag or belt.
The BeerNeck and BevNeck links above also feature other “cool” gadgets such as the BevClip for hooking a bottle inside pants pockets or a belt.