Place your kid in this iPod Bouncer stroller hybrid-thing from Combi and you're going to need the Light of Earendil's star to get it back.
Because it looks like a giant spider, get it?
Anyway, for $80, the Combi iPod Bouncer will literally rock and roll your infant with its bouncy legs and rear-mounted electronic sound and vibration controls. Just plug in your iPod and watch the fruit of your loins vibrate and throw up to "Through the Fire and the Flames" by Dragonforce or some other beat-intensive track of your choosing.
Counseling during your kid's teenage years, when they start having night terrors about the giant singing spiders that shake them with death metal beats is, obviously, going to cost a bit extra. [Think Geek via Red Ferret]