microSD max size
 

what is the maximum size microSD that will work with the 8320

You might want to check out the BlackBerryFAQs linked at the top of each page.

What type and size Media Card can I use in my device? - BlackBerryFAQ

I think the answer is 8gb but to be sure do some searching on google. Or just ask the person at the store for your phone; instead of asking in a forum. Because you'll always have someone tell you to search or use the FAQ. :)

Motorcycle Mama gave the correct answer.

Capacity depends upon your OS version, not your device. Go to the link posted by MM for the answer.

These forums are far more helpful then carrier's tech support. (and local carrier stores in my area)

Depends on your os. Go to options and click about. If it is 4.5.0.81 and above, you can use 16GB (like me). But if its smaller than that, only up to 8GB.