What most people don't realize is that some of the newer cell phones have a record feature on it.
I have a Nextel i730 and can record phone conversations. I use to have an LG something from Verizon. It was like the 2nd one that came out with the color screen and the flashy front. I could record on that too, but only their voice (assuming it was for getting directions.)
But most of the newer ones (including mine) record both sides. Good for those who don't have landline and can't wiretap (those radio shack suction cup things) a conversation.