Here's the app. that you guys are discussing. The site seems to be down right now.
Description:
Windows Mobile Monitor is a software application designed for cellphones running Microsoft Windows Mobile 5.0 or 6.0. The application runs silently and invisibly recording all text message and phone call activity that takes place on the phone. A desktop client application allows you to easily and quickly transfer the activity log to your own computer.
Unless you own the phone and pay the phone bill, spying on the sms and call usage with this app may not be legal, and in some countries it might be totally illegal. So use this wisely.
Download the Windows Mobile Monitor User Guide
here.