http://petewarden.github.com/iPhoneTracker/
but it's only for Macs.
However, you can have a look on a PC thus:
- Download SQLite browser from http://sourceforge.net/projects/sqlitebrowser/files/sqlitebrowser/, extract the files and run SQLite Database Browser 2.0 b1.exe
- Find your latest iphone backup folder in C:\Users\[your username]\AppData\Roaming\Apple Computer\MobileSync\Backup
- Open a command prompt (Start > All Programs > Accessories)
- Run the following command: findstr /M CellLocation C:\Users\Andykn\AppData\Roaming\Apple Computer\MobileSync\Backup\[latest backup folder]\*.*
- In the SQLite browser select File > Open and browse to the file found in the previous step.
- Select the "Browse data" tab and use the "Table" drop down to select "CellLocation".