From PCPhoneSoft:

The Skyjack Plugin converts your ordinary magicJack into a powerful dual mode magicJack and Skype calling product. Just dial * followed by the number you wish to call. For magicJack calls, dial you calls as normal. To call other Skype users, dial the Speed Dial number *1 to *50 you have associated with their Skype name in the built in Speed Dial table. For incoming calls, just answer your phone when it rings.

DOWNLOAD HERE!