Actually, I haven't tried it, and I don't want to. It is really nice, but when I need a mobile computer, I want it to fit in my pocket. The N900 can go into my pocket, and the iPad can't. The N900 can make phone calls and take nice photos. So if someone has an iPad, he must carry a few more devices with him.
And actually, I feel pity for that little girl on the linked video. At her age, she would really need to play with real toys and meet other children, not tied to a screen already...