This is somewhat a mess. Most phones have the Pop-Port connector, but some phones do support usb natively and other do not. Those phones need a data cable with a builtin serial to usb converter, like the ca-42 or the older dku-5. For an overview, see this archived page.
If you messed up like me and bought a ca-53, but you have a phone that only supports serial communication, you can build a ca-42 cable using the ca-53, a female usb port, some jumper wires and an usb to serial converter.
This only works using gammu and not with the nokia pc suite.
If you got a non-nokia ca-42 cable (sold on ebay as original nokia) with the usb id 10b5:ac70.
This is a third party cable which was sold on ca-42.com.
Using gammu on linux, this worked out of the box.
But it was a little harder on windows 7 and the nokia pc suite.
Unfortunately, archive.org did not contain the ca-42.com driver. Windows did not detect a driver automatically.
I tried forcing windows 7 to use the nokia ca-42 driver, but this resulted in windows freezing when the cable was plugged in.
I got it working by:
Now open the pc manager, configure it to use the right com port and the connection should work :)