... to the mic-in of your computer.
Please bear in mind, this is not a proper phone recording system, so there is just 1 file per execution. For example, if you run the script from 0800 to 2000 in one go (without any interruption in between), all the calls will be saved in 1 file.
To make it more robust, you can install NC_NET on the clients computer and setup Nagios to monitor them. ;-)
Hope it helps!
Cheers.