I have two of these cases and bought them back in February of 2007 when I first got my N800. One was purchased to house my little 40GB Seagate portable USB hard drive.. the other for my N800 since i didn't see any good cases back then.

The Case Logic hard drive case you showed is sturdy and safe--good for long trips and such. It even has some space to hold cables in a pocket inside. The downside is that it's VERY cumbersome in all other respects. There's no holes for any headphones or other ports nor buttons. I would leave the zipper open a tiny bit for headphones--but that still gives you a not-so-portable case, way too big for any clothing pocket anyway, to bring around with you.

I've also got the Boxwave black flexskin too. I find that this is an EXCELLENT skin--it's got that ODD squishy and rubbery yet the texture repulses dust and dirt to help prevent them from sticking to it. I really do like it and it has all the right holes and such. The only downsides--I do wish it allowed the kickstand to come out--but that's a minor annoyance. The MAJOR annoyance is that, once inside the skin, the N800 can no longer be mounted to the Nokia dashboard mount since it needs to be able to slide in and out. This shouldn't be a problem if you use a PDA holder that just pinches it to hold it in place--in fact, should be an advantage since it's now rubbery and won't slip at all.

I've got a third style of case coming in the mail soon.. I'll let you know what I think of that one as soon as I get that too.