This thread is old, but maybe some people will find this helpful.
I am using an older, smaller version of FTW (version 5) on my flash drive. I installed it using Portable App Creator (v 0.99 beta).
To make it work requires a few extra steps:
FTW refuses to install to a portable drive, so I created a directory C:\Portable Apps\FTW and installed it there.
When the Portable Apps Creator screen up asking for the location of the exe file came up, I moved the FTW folder into the Portable Apps folder on the flash drive, created an Apps sub-folder in the FTW folder and moved all of the FTW files into that sub-folder.
I then pointed Portable Apps Creator to the exe in the Portable Apps.FTW/Apps folder on the flash drive. Everything else went smoothly.
FTW loads slowly, but is fast enough after it loads.
Hope this helps someone.