To check what firmware version your Nokia 6682 is running on, just type *#0000# into your phone and the information will appear (no need to press the “Send” button). The most current version is:

V 4.62.0
28-10-05
RM-58
Nokia 6682

Update: This is actually the most current version:
V 4.65.0
24-02-06
RM-58
Nokia 6682

Learn how to upgrade your Nokia 6682 firmware at my Upgrading your Nokia 6682 firmware post.