If you have need to record conversations from your iPhone and can’t find a suitable application that will do the job there is a rather unattractive and bulky way of achieving this.
The awaiting inspiration website has posted an image of an iPhone calls recorder, which is a switch box that connects to your iPhone via the iPhone headset output port; although you need to use your computer to record you part of any convo.
On the other hand you could simply fork over some of your hard earned cash to gain such applications as SpoofApp or Recorder 10, or if all else fails one could simply hold a Dictaphone to the iPhone maybe.