>> I rarely see the cardboard cartons anymore, all the brands have
>>switched to plastic and those have handles....

The plastic holders fit the current plastic bottles perfectly (as well
as the waxed cardboard cartons that some stores still use for milk and
juice), and the larger handles are much easier to use. I still use a
couple of them regularly -- their only downside is that the handle takes
up more space in refrigerator door trays.

You can find them on ebay under the names "Handi Holder" or "E Z
Holder", at various (mostly rip-off) prices.

-- Larry