people look at me with amazement sometimes when im carrying Lucy in a sling (or a knotted scalf) . They often comment on what a good idea it is or how its a new thing that they've never seen before.

Well it's not a new thing at all, and Lucy and i love it.
sprockets of words from http://www.babaslings.com/babyslingsart_wisdom.asp


A pram or a cot can separate; a baby sling unites, as baby snuggles close to your body. Our western material values separate individuals from each other. Much education neglects the heart; our troubled bodies and minds separate the spirit. Likewise, we separate ourselves from some of the deepest human bonding needs between parent and infant. For a baby in a sling, mother's breastmilk is easy to seek and find. A parent (including fast-growing numbers of fathers) is all the more likely to hold baby, because her or his hands are free for other activities.
In our own culture's non-wearing of babies, are we, then, missing some of the deeper joys of bonding? For example it is known that babywearing stimulates levels of the mothering hormone prolactin. In not following the babywearing practice of so many old cultures, are we seriously depriving our children of one of the greatest of benefits to childhood development?

other benefits mentioned

"Many scientific studies now show how a carried baby receives the exact essentials of pressure, motion, pleasure, warmth, security, sound.

Baby-carrying stimulates optimal development of the cerebellum of the brain.

Sling use tones muscles, increases cardiac output which increases circulation, promotes respiration and digestion. Infants experience reduced rate of wind and colic. Neck and shoulder muscles are stronger, there is less head lag

Sling-worn infants are at the center of activity - a precondition for the development of empathy, and esteem of both self and other, rather than a laying of foundations for lifelong egocentricity.

The development of mutual reading of cues is encouraged and speeded."