Paperftdi

A good source of very cheap USB-serial adapters for programming bare-bones Arduinos.

• http://txapuzas.blogspot.com/2010/07/cable-de-programacion-para-arduino-ftdi.html
• http://jethomson.wordpress.com/2010/02/21/diy-usb-to-serial-cable-for-3usd/

Random find in the two box system: -

• Mobile Action MA-8910P USB Data Cable for Sony Ericsson- T226, T306-T316, T610, T616, T637, S710a, Z500a, T630

  Class: Ports (COM & LPT)
  Device: Prolific USB-to-Serial Comm Port (COM7)
  No resources used.
  Device Drivers:

OK, so has a prolific PL2302 or equivalent!

Cable has 4 conductors - all go directly to single pins on the phone connector