The method used in this guide is the original method devloped. Using Grub4DOS to create your bootable drive is easier to setup and provides much more flexibility in booting multiple configurations.
Repeated posts on the Acronis True Image Support Forum requesting instructions on installing True Image on an external USB hard drive and being able to boot from it have prompted me to create a guide on the subject.
Including both general instructions for those familiar with True Image and step-by-step instructions for those new to the process, hopefully anyone with True Image 10, a USB flashdrive and USB hard drive can successfully create an Acronis Bootable USB Hard Drive. For those still using True Image 9 (build 3,677 or later), the process is only slightly different.
This will allow you to boot into the Acronis media (True Image, Disk Director, etc.) from your storage drive with no need to boot from the rescue cd or from a flashdrive. If you have created a BartPE cd or flashdrive, you can use the same instructions to boot BartPE from the USB hard disk.
The original thread on the forum can be found here.

The PDF guide (last updated September 29th, 2007) can be downloaded here:

If you have problems creating a bootable flashdrive or hard drive, please see the troubleshooting page: Why won't my Flashdrive or USB Hard Disk boot?