asterisk users - Dec 2009 - asterisk billing transferred calls

Hi,

I'm looking for an application to show all the calls received/made 
including (this is very important!) transferred calls because I need to 
track all the time spent on the phone by all my employees.
There is a list here but they are too many to try them all: 
http://www.voip-info.org/wiki/view/Asterisk+billing  :)
Any suggestions?

Thank you

Giorgio