I am a HUGE fan of baby-wearing (coined by Dr. Sears) – or having your baby on your body through the use of a sling, pack, etc. It keeps baby near and allows you to be hands-free to get things done. I have two slings, two carriers in which baby is worn on your front and can face forward or towards you (Bjorn and Evenflo), and an Ergo, in which baby must face you, but can be worn on the front, back or hip. I love them all for different reasons – my slings are easy to throw in a diaper bag and take with, the Bjorn is GREAT for once baby gets bigger and wants to face forward and see what’s going on, the Evenflo is good for the same reason, but has a hip strap so once baby is a little bigger, I get a little more support, and the Ergo is the most comfortable for me and has lots of versatile carrying positions. The Bjorn is great for an infant (facing them towards you) but once baby is about 12-15 pounds it is really not comfortable for you. The Ergo is awesome once baby is a little bigger, but I don’t like it for a small baby.
That said, there is some debate about whether certain carriers (namely those in which baby faces forward and/or the legs dangle straight down, like my Bjorn and Evenflo) are bad for baby’s spine/hips. I can’t find anything conclusive one way or the other. Here are some interesting articles: