I was consulting with a customer, and we hit a point where they needed to check a change into source-control. They were using a VCS that I'd not used before, so I asked how to do it. The answer was "Oh, let me get Tim, he's the one who knows how to check stuff in." It took 5 minutes or so to find Tim, and then a few minutes of him moving through the "interestingly designed" GUI of their VCS he was able to get it checked in, and then another couple of minutes he was able to enter a description into their change-tracking system to pend for code review (required to merge into their mainline branch).

I overnighted a book from amazon on the VCS and process management tools they were using, read it the following night, and the next day took about 15 minutes to talk to Tim and then another 30 minutes writing a perl script that prompted for the 4 bits of information they needed and automated the check-in and change-review request. Total billable time spent on this 45 minutes. Time saved by having this script around the 2 weeks I was with the customer at least 2 hours (10 minutes of my time were wasted every time a change needed to be submitted previously!).

Every time I visited that customer in the future, the group was still using that script I wrote. Also every time the manager wanted me to assure him I wouldn't waste time by writing a script like that because that's not what they were paying me for.