I've recently bought something similar for both my DS and my iPod at www.bestskinsever.com. The application process is kind a confusing at first but after I got it all sorted out I was very satisfied. There are no instructions given and it's shipped in a regular envelope but there are instructions on the site and the skins arrived in perfect condition (except for one of the skins, but they promptly shipped me a new one without even asking for the damaged one. They even threw in a free body skin for my brother's phone. The reason it was damaged wasn't even their fault, it was my postman's so yeah, customer service is also pretty good.) Anyways, it's been a week or so since I've applied them and I have to say that I'm very satisfied, especially with the iPod skin. It looks and feels great and tough. I'd highly recommend them and their prices beat invisible shield's by a good deal too.
A side note: Their DS touch screen protector wasn't great but I didn't really care because I already had another one.
Edit: I feel the need to clarify the damage part because on my second read through it seems kinda confusing. The skins were not bent or anything, it's just that part of the skin stuck to the invoice because the postman ripped the plastic part of the envelope that shows the address causing rain to get through causing the skin to stick to the invoice. It wasn't even a big deal, there was just a blotch of paper stuck to the skin making the whole invisible aspect of the battery cover of my DS Lite skin null. That was an extraordinary circumstance I think so I wouldn't be worried about the shipping aspect of their skins.