I bought the Apple Smart Cover (Orange, Polyurethane) and it really is quite a neat little product, in terms of design at least.
It doesn't 'clean my screen', it doesn't 'remove finger prints' but it does offer some protection the the front as well combine to make a pretty super little stand.
I've noted that in less than a week of being used in coffee stores and placed in my bag, it is already changing colour, that is to say it's already picking up dirt. It looks like my old white MacBook where I had to regularly clean it, these alu-MacBooks (this post, right now, is probably the first time I've used my MacBook for simple web activities since buying the iPad and that's only because I needed to remotely connect to the office and we don't currently have a tool in place to allow me to use my iPad) seem to 'stay clean' or perhaps 'hide the dirt' way better than my first macbook ever did.
But the biggest problem, by far with these smart covers is that they only show love for one side of my iPad!!
I am planning to buy some kind of skin/wrap for the back of my iPad in order to give the back a little protection from scratching etc. I just need to slow down on my out-goings at the moment or I'm going to get a smack around the head if I buy anything else for me I think... ;P