Some time ago HaD featured a hack I made with my friends: http://hackaday.com/2010/08/14/portable ... n-testing/
I have made an upgraded version of the device:
It's a a small wifi router (La Fonera) running OpenWrt, with an attached color touchscreen LCD driven by an STM32 uC.
The uC communicates with the router via a serial terminal, this allows to run programs on the router and show their output on the display, while the touchscreen makes it interactive.
The device fits in a 150 mm x 100 mm x 28 mm box and can be powered with an external battery pack.
So far I've only implemented some simple demo attacks to prove the device works, hopefully I'll update it some day
More info on my blog: http://emerythacks.blogspot.com/2011/04/wifon-20.html