I never could understand this. As a kid, I remember owning 12 or 13 hamsters over time and what I learned is they are stupid, mean cannibals that prey on their own young. Now, as I work with them at the pet store, exposed to dozens at any given time, I consider them the most worthless pet imagineable. A hermit crab sounds so much more appealing.
(See more hamster photos at this blog)
Let's think about this. Yes, they are cute. They're frickin' adorable, but that does no one any good if they bite! And they do. Occasionally you may stumble across one friendly enough to enjoy handling (usually male), but when he dies and you try to replace him for your kids, you're going to have a task on your hands. I've been bitten so many times by these critters that I no longer place my hand in the cage. You want it, you put your hand in there and find out which one likes you.
And they eat their young, so don't let them breed! It's not "family project"-worthy. Trust me. My dad found out the hard way.
If they don't eat them, then you have a bunch of hamsters on your hands that WILL inbreed with one another if left together.
So...what's the allure here? Am I missing something? Just because they look precious doesn't mean they behave that way. They can't bond with you really. They can't be played with or handled much. They destroy anything and everything left near the cage (curtains especially). They smell bad. And they're notably inbred (click here for history on hamsters).
Not a suitable pet for kids in my opinion. That goes for gerbils as well. But if you simply must have a hamster, make sure you provide it proper care.