"If only," I mused, "there was a small hand-held computer that could be programmed to do the sight reduction for me." Then I had an epiphany - I had just such a device in my pocket! My iPhone was entirely suitable for this task!
Like a flash, I did a quick app search, and found a sight reduction app (for $49.95!) that was just the ticket. That seemed like a lot, but loading all the ephemeri for a large collection of heavenly bodies would be a daunting task, and certainly deserved appropriate compensation.
And then the blocks slowly fell into place in my (perhaps slightly wine-impaired) brain. Wait a moment... if I have an operating iPhone, I already know my position on earth to within a few feet, thanks to its GPS. D'oh.
But for an even bigger d'oh, what was the guy who wrote the iPhone app thinking?