an updated howto on a portable/usb cygwin installguide?

Is there an updated howto on a portable/usb cygwin installguide? Since 1.7 cygwin no longer writes to the registry so I was curious if there were any changed on making a portable install and/or a end all guide on the process. -- Problem reports: http://cygwin.com/problems.html FAQ:

Re: an updated howto on a portable/usb cygwin installguide?

I noticed with your setup I'm stuck with [loggedinuser]@[hostmachinename] ~ as my prompt is there a way to change the $user variable without editing /etc/profile ?? mainly to intercept that pesky USER="$(id -un)" to change it to something of my choosing in the bat file? ie T