I have alot of experience with Gizmoskin.com i have had 4 of their cases for different phones.
I got the treo 750 case, which is within a mm on each side.
its awesome. I love their cases, secure, slim and ratcheting clip - the leather is TOP quality.
there is a little play at at the top of the case as far as fit, but it doesn't bother me and there is no worry of the phone falling out or anything, but it has some freedom to shift in the case.
FYI, the standard shipping is REALLY slow - to florida it can take like a good 2 weeks, cause they ship from canada. On the other hand, with overnight, ordered on thurs, shipped friday, at my house monday before 9 am. Pricey, but, it was there.
Good Luck!
fyi, with the case set horizontally, the phone feels like it weighs nothing. I wear alot of gym/ basketball shorts that have no strong waist support and it does not pull it out at all. i'm super happy.
or if you want something more exotic
http://www.gizmoskin.com/index.php?category=3&subcategory=56