There is also a free service here:
https://www.freeconferencecall.com. When you sign up for a free account and some readers are open to it, they call your number, then you set the call to record (*9) - all done through your phone. It's just like a regular conference call: you get an access code, and there is a dial in code for callers. Afterwards, you can email the call to yourself or go back and replay it since the call is stored up to six months. It's completely free. They will transcribe it for you for a fee.
I haven't tried it but I wonder if you could conference a call to Keen then add it to the existing call, so you can record those too.
You can select either an 800 number or one with a local area code.