You will need
- Cell phone or smart phone that supports installation of additional applications along with the free space on the memory card;
- app voice recorder for mobile phone;
- external recorder (computer, tape recorder, etc.).
For starters check to see if already on your phone voice recorder along with the factory settings. To do this during a call to view all available for the execution of the function. Perhaps you will find the option "Enable recorder". Then you just need to activate this menu item, and then the entire conversation will be recorded to the phone memory. These recording you will easily be able to listen to or to throw on the computer.
If no recorder on your mobile, you can install it yourself. To do this, connect your phone to the computer via cable, IK-port or Bluetooth. Perhaps, you will have to install the drivers. Then copy the voice recorder app in the phone memory. After that, really mobile install the copied application. In the settings of the recorder might be such a function as "start recording automatically". Then you don't need to do it manually. The majority of these applications when you start recording, make a distinctive squeak. But if you search, you can find and suppress the squeak of tape.
If your phone does not support installation of additional apps or you for some other reason can't install a recorder on the mobile, you can record sound on another device, e.g. computer, player, etc. To do this while talking turn on speakerphone and zoom in to the speaker phone recording device. The recording quality is, of course, be quite low, but the conversation can still be understood.