Remember how 4Moms's mamaRoo rocked the baby-gear world when it was introduced? The company hopes to do that again when the rockaRoo ($160) hits store shelves this month. An infant seat for the modern age, the rockaRoo inverts the traditional swing's pivot and places it beneath the seat rather than above, so it moves smoother (more like a rocking horse) than an actual swing. With an MP3 hookup, reversible toy balls, and both bouncing and swaying motions, the seat is a great improvement on the traditional swing. Not only that, but the seat is actually smaller than your traditional swing, saving space in the nursery too.