At first I assumed "that should be easy on the iPhone," but soon found out how wrong that was. Apple makes it very difficult to record your iPhone conversations directly, perhaps to prevent people from secretly recording calls. None of the voice recorder apps will take input from the Phone part of the iPhone.

The only one that comes close is "Recorder" by Retronyms. Recorder works by using a server in the cloud as an intermediary in the recording process. To use Recorder, you must first purchase minutes - the cost is only $1.99/hour, so it's possible to test without a big investment. Call your contact, dialing from within the Recorder app. Recorder dials the external server, then the app exits and switches you over to the iPhone's native Phone app where you can use all the normal phone features during the call. So you have access to the keyboard for making menu selections, your contacts, etc.

It all works pretty much as advertised. Unfortunately there is a slight sound delay introduced by the intermediate bounce of the call to the server. It ranges from a little irritating to very noticeable. The call can also occasionally disconnect if your wifi or 3G signal is poor - it needs more bandwidth than a normal call. I used it for a couple of interviews then went on a search for a more reliable method. it is good in a pinch, though.

Another method you can try is to set up a free Google Voice account. If you first call the Google Voice number, and let it flip over into voice mail, it will start recording the call. Then you can conference in the conference call. Google Voice may announce it is recording to everyone on the line, but that is fine for this purpose. If you are lucky and everyone speaks clearly, Google will even transcribe the call for you. Unlike Recorder, Google Voice does not add any delay, since the call is not being routed through their servers before it gets to you. But it is a somewhat complicated method, and I was hoping for something drop-dead simple, that would always work.

I next purchased a cheap suction cup mic, the type that attaches to a phone receiver, hoping that I could plug it into the headset/mic jack on the iphone and record direct in to any of the voice recorder apps. Unfortunately it takes a fairly strong signal to make the iPhone recognize the external mic and switch from the built-in mics. So I had the choice of putting a preamp or mixer in between the mic and the phone, or trying something else.

The next thing I tried was using the suction cup mic with an old Olympus digital recorder I had laying around. That works, but the signal is still pretty weak, even with phone at top volume and best settings on the Olympus. So, I am ordering a little Olympus phone mic, hoping it will provide a slightly better signal. Updates to come soon, when I've had a chance to try it out!