After watching my wife zip up our daughter into her coat, I realized that with a few inexpensive tweaks, one could have a very handy carrying coat on one's hands. The trick will be that the coat would have a cinch-able band on the inside that could adjust to keep the baby snug. Baby would kind of sit perched on the band, head on mom/dad's chest.
The coat would be a normal coat in all other ways, except it would likely have a few more pockets. The problem we face when going out in public with baby is moving baby around when it's cold. We like the Ergo Baby carrier, but it still requires some finagling to get right, and by that time the baby is fussing or you're already in the store/restaurant. If all you had to do was drop the baby onto the internal perch and zip up your coat, you're in 7th baby heaven! Wah!