Yes, Dialectic can dial using the magicJack device. To do this, Dialectic communicates with the magicJack software using a custom AppleScript Dial Method script. This script, along with an AppleScript application that will configure Dialectic to dial with this script and, by extension, the magicJack device, is available from the resources page.
To configure Dialectic properly, please download the configuration application from the resources page:
http://www.jonn8.com/dialectic/resources/GeneralDialingConfiguration/ConfigureForMagicJack.zip
Note: One caveat to this is that dialing from Dialectic to the magicJack software requires GUI scripting to be enabled on your system. To enable GUI scripting, check the option to “Enable access for assistive devices” in the Universal Access pane of the System Preferences application. The configuration script application will check to see if GUI scripting is enabled and, if not, open this system preference pane and prompt you to enable the option.