Connect your cell phone with your PC/Lab top by the serial port.
Download / Modify the ringer tones for your Nokia 6100 cell phones.
Modify the Startup and Operator logos.
Edit mobile phone numbers on your SIM card.
Edit / Send picture messages via your PC.
Make full use of service software that requires M2BUS connection: e.g. Nokall - All Nokia Tool - Nokia2000 - Wintesla - Winlock - for removing simlocks etc.