Figure I'll toss my hat in the ring.
It's been really neat to watch Apple go from making a product that people opening mocked on release (large iPod Touch, anyone?) that has now made it's own market, one that people are (again, like the iPhone) trying to catch up to, and is actively stealing marketshare from the netbook market.
As for use, there are lots of times I find myself wanting an iPad for certain tasks (couch surfing, taking notes in class, etc) where the iPhone doesn't do it, and a laptop is too cumbersome. It definitely fits it's niche.