I have used it before and very seldom is it really used. It will ring to my cell, office line at the office and my home office along with my home phone number (distinctive). It works pretty good when you need it to, but sometimes it gets confusing. I am not sure for some but I have a caller ID issue with it.

My home line is Vonage, my cell is Cingular and my work VOIP is P8. The caller ID works on none when coming through the GC line.