I bought this for use on my Nikon D80. I was hesitant, only because I wasn't sure how I would use it. Starting out with the D80 though, I wanted a lens that was simple to use, and that would show me what the camera was really capable of, without spending a fortune!
I'll just begin by saying what everyone else has said. This is an essential lens for anyone, but in my opinion even more essential to those new to DSLR's. There are lots of cheap, mediocre lenses out there, that result in mediocre image quality. That's what most beginners will start out with. This is not one of those lenses.
There are many comments about the cheap construction of this lens but I won't penalize a $100 lens for that. I have used $600 lenses that feel as cheap. The lens is small, compact, and seems well made. I don't feel like the lens is a toy, or that it's not going to hold up to heavy use. I think the build quality of the lens is more than adequate, and can assure you that you don't want to miss out on this lens because it doesn't weigh a ton, have gold striping on it, or feel like a $2000 lens! There's nothing about the build quality that affects it's performance.
Anyway, the only other thing I'll say is that the lens is so good that I find uses for it. I want to shoot with this lens as much or more than any other lens I have because it is so good, and because it makes me more creative. I am always looking for new ways to use it. It's great in low-light, it's great hand-held, it's incredibly sharp...oh and the bokeh is incredible, not like anything you will see on the slower zoom lenses. It's a great lens to learn a new camera with because you won't be fiddling with the lens or wondering if it's the lens quality that is messing up your shots :-).
If I could get as fast a zoom lens with the same image quality, for anything near this price I would be in absolute heaven!