said by ecappabianca :
I am currently using MagicJack on OSX. The solution to recording calls via Mac is to download a program called 'Audacity'. once installed choose Preferences ->and change the device to: 'Unknown USB Audio Deivce', and each time you call someone and want to record them, you let the program run/record. Then save and export as .wav file. It works quite well.
This sorta works with Vista too. But Audacity only records my end of the conversation. Certainly though, this is a problem with the stereo mix settings in Windows rather than a problem with Audacity.