I have an iskin left over from my old 20 gig 1st gen ipod - it fits the new 40 4 g damn near perfect - the wheel is just a bit smaller that the hole in the silicone jacket - I'm set until the new iskin arrive!
Glen
it is snug enough that it slides in very easily and does not slide out when turned upside down unless shaken- but it is a little loose on the sides - I will use it until a skin comes out for the 4g...don't get the opin I'm saying it's perfect but the control wheel matches up on the front - people that don't know Ipods wil think it's made for the 4g...
I'm seriously thinking about making this my permanent case for the the 4g - I have had it in an out of my briefcase, popped it off several times to sync and charge and it fits good - slides out much easier than a skin made for this size and since the hole for the click wheel is just slightly larger than the wheel itself - you can feel the edge of the wheel and spin it easier than rubbing into the case edge - I think I'm sold...
I love it when I find something in my junk drawer that comes back to usefullness...
Not a big deal, I don't think Apple was considering it a new generation at that point. They did call this new one a ???4th Generation??? on the web site, but I don't remember them using that terminology before
If you want to buy a 1st Gen iSkin, I recommend getting one made for the 10GB 1st gen model, the thickness is very close.
1st Gen 10gb: .72
4th Gen 40gb: .69