MobileLog is a call manager that lets manage incoming and outgoing calls and sms. Enables grouping of calls by contact, gives you the possibilty to delete a record of a single call, has the time tracker feature that you can set to terminate the call after a period of time that has been previously set.
It can be downloaded from Cydia for free (the cracked version).
Just check it out Start from $0.01 for real.