Yep, hold the menu button while powering on. The camera will display the firmware version number for a few seconds before doing its normal power-on stuff.
AFAIK, Pentax has never updated the firmware installed in production cameras, so, if you haven't updated it, chances are it is still version 1.0.
The latest version is 1.30. If a new version comes out, you will probably read someone posting that fact here. Or, you can periodically go to
Pentax Imaging - Home and follow the links for self-support.
Downloading and installing the firmware is very easy. There is an instruction sheet on the same webpage as the firmware download. Just follow those instructions and you shouldn't have any trouble.
BTW, the versions are cumulative. That is, just d/l version 1.30 and install it. You don't need to install 1.10, or 1.20.
Hope this helps.
Paul Noble