I just received a Piel Frama leather case, Crocodile style black, to review for my palmOne Treo 650 and it is beautiful. The case is very lightweight, adds very little bulk, has a nice mesh speaker opening cover, has cutouts for easy access to everything, does not put plastic over the keyboard (like other cases I have tried on devices with keyboards), and is very well constructed. I have a Piel Frama black crocodile case for my Dell Axim X30 and the case alone has kept me from getting rid of the device. My wife love the look of these cases as well and the Treo 650 can now safely ride on my belt instead of me having to try to find a pocket for it.
These Piel Frama crocodile cases run over US$100, but they are each individually hand crafted in Spain and I could not be happier with the quality and smell of the leather. If you are looking for a PDA case then I recommend you check them out. They do have styles that are much less expensive than the crocodile model and some US online retailers, like StylusCentral.com, sell them as well.