Keychain Access Hangs Solved
After months of having serious issues with Keychain Access hanging my machine for 15 minutes at a time, I finally found the solution. The problem presents itself when you choose to allow a software program to access your keychain after you get the "Software on your computer has changed and wants to access your keychain" dialog. Clicking Allow results in a complete system hang that can only be remedied by a reboot.
Fortunately, someone smarter than me found the solution. I followed Solution 1 at the bottom of the article to get rid of my corrupted CodeEquivalenceDatabase and I'm back up and running.