In Mac OS X 10.7 'Lion,' Apple has introduced the Recovery HD as a means to troubleshoot and reinstall the OS, similar to the install DVD for previous versions of Mac OS X.  As the result of some unforseen event, the Recovery HD may become unavailable to you, and plus does not include the functionality of TechTool Protogo. Using Protogo, you can create profiles and devices to supplement, backup and improve upon the functionality of the Recovery HD - including all the capabilities of TechTool Pro 6.

Intel/PowerPC Profiles

With these profiles, you can create a device with a minimal OS and an installation of TechTool Pro. Think of it as booting from a DVD without all of the performance loss.  Put it on a USB Thumb drive for a super-portable diagnostic tool.

Basic Profile

With this profile, you get a slightly larger installation of the OS, including the Finder, TechTool Pro, and several Apple Utilities.  You can even add your own.  It will fit on devices as small as 16 GB, along with both of the above.

Full Copy Profile

You can also take the kitchen sink.  With this profile, copy the entire contents of your Hard Drive to another Hard Drive.  With enough hard drive space, you can take all of it with you.

Mac OS 9 Profiles

If you have or take care of legacy Macs, you can add a Mac OS 9 profile that includes TechTool Pro 3, as well as any of the above.  Just add a Firewire device.