I posted on this item when it was given to me by my Mom back around Mother's Day, but I think it definitely qualifies for the list.
It's called the Beaba Babycook, and you can get it from William-Sonoma.
I always thought that making my own baby food would be pretty extreme - lots of extra work and complication that I didn't need, but this little machine makes it so easy. It does everything all in one container - steams, purees, and reheats - all done in fifteen minutes. And it tastes pretty darn good (yes, I have tried it on occasion!) Nothing beats knowing that your babies are getting fresh food with nothing chemically added to it - especially in households like ours with food intolerance issues (we have a gluten-free kid in house). AND, it's a heck of a lot cheaper than buying those little jars at the grocery store.
OK, so I can't say this is truly essential, but it sure does make my life easier.