Nuu MiniKey for iPhone 4 previewSee all photos
The first thing you'll notice, and you really can't help to otherwise, is just how bulky it is (we've been told 20mm in thickness, which is more than double the iPhone 4 solo). It seriously adds a strain to your pocket. That said, once the iPhone 4 is in the case, it's not going anywhere -- the case fits snugly around the device, and it takes a good bit of effort to separate the two. A little too effort much, in fact, to pry one from the other. The slide-out mechanism is actually quite sturdy, although with just a hint of hinge flexibility when it's out.
As for the keyboard, the keys themselves are laid out well enough, although we wish the delete key was in the upper right hand corner and not right above the return key. They're snappy and have a decent bit of texture, but are still much too small for our liking -- we'd love it to stretch entire span of the case, especially since our fingers couldn't help but make erroneous clicks. A power button in the top left lets you toggle between off / on and somewhere in between, where the device knows to turn itself off after 10 minutes of idleness. Behind the keyboard there's a longer button for toggling between the physical and on-screen QWERTYs (pictured, right) -- we ended up using that more than a few times. Due to the the height of the case, a sharp enough light can cast quite an annoying shadow over the top row. There's also no backlight for the keys, so don't expect this to be very functional in the dark settings. Battery life is said to be up to 36 days on standby and charges via micro-USB, although we haven't had it long enough to really push that to the test.