Recently I have worked with a number of families who have been interested in using the Montessori approach to sleeping for their babies. This method is much more gentle than other methods and encourages independent sleeping.
The idea behind the Montessori Method of sleeping for babies is that the baby is placed on a mattress on the floor in a bedroom that is totally babysafe. This is done when the baby is ready to sleep independently, sometimes as young as 3 months. The baby has the freedom move around the bedroom as they choose and sleep on the mattress when they are ready to go to sleep. Over time, the baby understands when they are tired and recognises that the mattress is the place they sleep, so when they are tired they go to the mattress and sleep. Lovely!!
The families I have been working through this with have had babies of varying ages, and are generally using it as a method of sleep training to fix a problem rather than a natural progression from sleeping in a Moses basket or co-sleeping. It has been working very well as a sleep solution, particularly where parents refuse to leave their baby crying for even a minute or two. They can sit with their baby in the bedroom while the baby gets used to falling asleep in the new environment, and go back and help to settle them through the night as they cut out night feeds. I have been guiding them through the process and advising them of the right time to move on to the next step. They are all going at their own pace and are really happy with the progress they are making.
It is not the right method for every family, but it is the perfect method for many families.
Some useful links are:
http://aidtolife.org/movement/movement1a.htm
http://www.howwemontessori.com/how-we-montessori/please-read-about-us.html