By looking through System Information I discovered that I have several hundred old PowerPC apps that won't run under Lion without Rosetta any more. I'm OK with that, but, short of manually deleting old PowerPC apps one-by-one, is there a way to purge my Mac Pro of all PowerPC apps and related code in a batch fashion?

As I mentioned in you can locate the PowerPC applications on your Mac by opening System Profiler (Snow Leopard and earlier)/System Information (Lion), choosing Applications, and then sorting by Kind. The problem is that you can't then delete applications from within System Profiler. Additionally, there's no way to create a Smart Folder or Spotlight search that searches based on PowerPC code.

But, there is a way. And that way is AppleScript. Copy the following script and paste it into AppleScript Editor (found in /Applications/Utilities):

set the searchResult to do shell script "system_profiler SPApplicationsDataType"

set thesePaths to {}