Another great quote by Ron Jeffries (this time picked up via MemoRanda):
"The only time not to automate a test ought to be if we are never going to want to run it again. But it isn't. The more common time we don't automate a test is because it would be 'too hard' to automate it. That is, however, not really a property of the test, though we like to put it that way. It's really a property of our own test automation capability and tools."