The developer of Hub++ released Phone Tap awhile ago to help record phone calls. Now he has updated the app to bring headless support on OS 10.2.1 now that it is available. Now you no longer need to fire up the app or have it running in the background to be able to record the call. On the other hand you still need to have the call on speaker phone to get the full conversation recorded.
Check out Phone Tap for $2.99 in BlackBerry World