asterisk users - Feb 2005 - logging events with time stamps

i want the to find out the delay between two events:
1) the instance a call is recieved on an FXO port and the
2) the instance a SIP INVITE is sent to the SIP destination.

i need to attach timestamps to the events before logging them.  How can i:
1) log `ALL' events.
2) Attach timestamps to them?

thanks
m.smadi