Hi all,
For your information, the Amontec JTAGkey-Tiny works with OpenOCD and it address the hobbyist and student market. The JTAGkey-Tiny is very close to the parallel port Wiggler price but comes with the USB port advantages. The JTAGkey-Tiny uses the same USB drivers as the Amontec JTAGkey! If you already have installed the JTAGkey on your PC, you do not need to install the drivers again.
JTAGkey-Tiny:
Priced at €29.- , the JTAGkey-Tiny fits the hobbyist and student budgets.
The JTAGkey-Tiny plugs directly into the application board’s 20-pin JTAG connector (Multi-ICE compatible) and uses a mini-USB cable to attach to the PC.
JTAG IO auto-sense voltage : from 2.8V to 5V
http://www.amontec.com/jtagkey-tiny.shtml
JTAGkey:
The professionals would tend to select the more expensive JTAGkey for its strong ESD protection, for its over current protection, for its power filters, for its high speed and strong Input/Output buffers, for its LEDs and for the flat ribbon cable that attaches to the prototype system.
The also has an integrated USB cable fitted with a ferrite filter 
!
JTAG IO auto-sense voltage : from 1.4V to 5V
http://www.amontec.com/jtagkey.shtml
Regards,
Laurent