I have yet to find a good case for my 860. I went around Akihabara and Den-Den town till I was blue in the face, but all I could find were those leather wrap around wallets, which come in a couple basic types:
1) You have to remove the extra clip off the battery cover to clip the 860 in. Unclipping it leaves the cover loose, and carrying around the tiny clip without losing it isn't really an option.
2) You put some sort of sticker (Either smooth, sticky vinyl or velcro) and it sticks to a similar base in the case. Not a bad idea, save for all the cases I tried seemed to be made for the smaller 7xx series without the extended battery, and wouldn't close properly around my 860.
No matter what, they compromised on protection and left the edges exposed so you can just flip the top half under the unit for use. They also added too much bulk - the extra thickness of the case made the already large unit unpocketable. Plus, I found that the leather flip wallets made the unit more awkward to hold while using it.
I tried to find a zip-up, pouch, or slipcase style case, but I couldn't find any evidence that something like that existed there. I'd really like to know what they use for cases (other than a drawstring back) for their electronic dictionaries like the Canon Wordtank - which are about the same dimensions at the Z.
Now that I'm back in Canada I still can't find anything - most of the generic cases for PDAs are just too small. Ideally, I'd just like a leather slip case that I can tuck it in to. (I've used the leather case that came with my palm professional for 6 years now - my Palm Vx and Client TJ35 both fit perfectly with their screen covers on.)
I don't really like the Trisoft case linked to earlier, either. The fact that the leather slips over the keyboard and sits between it and the screen worries me. Anyone actually used one of these?