Making models or putting together Lego sets is a great activity to get your kids into. It allows them to use their imaginations while also learning how to follow instructions and pay attention to detail. What's even better is when the finished product is something totally badass like, say, a T-Rex skeleton that stomps and roars.
Oh, that's exactly what the Skeleflex T-Rex Powerflex Lab is? Awesome. Simple pop together all of the bone segments via their snap-together ball joints, and you'll create a flexible T-rex model. Put it on its powered bas, and it'll stomp around and thrash its head. I'd like to see your Lego models do that.