My 6 year old son is obsessed with Legos! I have to brag that I feel he is very advanced for his age. He does really well following the directions in the large kits and even better dreaming up his own creations. He has amazed many people with his creatitivy.
Here is one more, a car complete with drivers:
The coolest thing is you can order your creation from Lego complete with instructions so you can build it with real blocks!
If you have a kid who likes Legos, I suggest you check out this site, it really is a lot of fun.