Don't let anyone tell you that feeding solids to help a baby sleep better at night, is just an old wive's tale.
Ever since I started giving Baby rice cereal (with or without the addition of vegetable or fruit purees) every day, she's been sleeping better. Not twelve hours straight or anything, but in 4- and 5-hour blocks instead of 2- and 3-hour blocks.
Unfortunately I haven't necessarily gotten any more sleep as a result, because some nights I just can't get to sleep even when I'm tired. Maybe I should increase my own carbohydrate intake.