Gelaskins have created such amazing and unique designs to make your Kindle standout. My friends are always commenting on the design and how sleek it makes the Kindle look. There is a great range of designs although I'd probably recommend going for a less 'busy' design (the Enamored Whale is perfect) otherwise it can be a bit detracting when reading (You can just have the back skin if you wish as they are separate).
Application of the skin was very easy, a little difficult to get aligned with the keyboard but all in all no hassle. The skin is really easy to peel off, and unlike screen protectors for your IPhone, you get no annoying bubbles. There are also separate stickers for your page turning keys and square 'ok' button which I also think is a nice addition.
The real difference you'll find with Gelaskins (other than a unique design) is the change in the feel of the Kindle in your hand. The skin is very smooth compared to the textured and durable feel of the actual Kindle. It took some getting used to at first, I felt the Gelaskin was too sticky/sleek feeling but I've adjusted to it fine after a while. Some may find they don't like the sleek feel so bare that in mind when buying.
I've had my Gelaskin for going on 4 months now and it holds up really well. I carry my Kindle in a M-Edge leather case and I'm continually taking the kindle out of the case (I hate the bulk of a case!) & putting it back in for transport. Despite this, the skin is pretty scuff free even in the corners where my case holds the kindle in place.
To sum up: absolute thumbs up for Gelaskins! Design and application were perfect. Although changes texture of the Kindle (can be a positive of negative)