Baby leg warmers are one of the very few baby clothing which will last you for a long time. They can be worn since newborn all the way up to their toddler years. They are great to keep those tiny limbs warm without the hassle of putting on tights. Miss Kiki wears them from Fall to Spring on top of her socks under her pants, to keep the small opening between the pants bottom and her socks warm. Considering that it snows from October to May where we are, I think that's a pretty HOT idea!
The best known brand for baby leg warmers in North America is Babylegs, but there are a lot of other manufacturers that make them and a lot of times a whole lot cheaper. Unfortunately, though, I can not get those where I live easily.
I found this tutorial online on how to convert a pair of socks or knee highs to a pair of baby legwarmers. It's so easy to follow the instructions! Have fun!