The client at https://github.com/zack-bitcoin/X-change is currently set up to connect to my demo exchange.
The exchange is at http://3uc1id.no-ip.biz/ but you wont be able to trade currencies until you run the python code.
Security is a little different with this exchange. It is a lot more secure, but users have to run a python program to connect.

you need to install these things:
python2 at http://www.python.org/getit/ (get the 2.7 version, not 3.3)
https://github.com/vbuterin/pybitcointools

To run this program, put this in a terminal:
python gui.py

It uses the browser as a GUI, Send your browser to:
http://localhost:8090