Writing code in a compiled language is one of the last things that still can't
be done instantly on a garden variety home computer. If your compilation
process takes more than a few seconds, getting the latest and greatest computer
is going to save you time. If compiling takes even 15 seconds, programmers will
get bored while the compiler runs and switch over to reading The Onion, which
will suck them in and kill hours of productivity.
Debugging GUI code with a single monitor system is painful if not impossible.
If you're writing GUI code, two monitors will make things much easier.
Most programmers eventually have to manipulate bitmaps for icons or toolbars,
and most programmers don't have a good bitmap editor available. Trying to use
Microsoft Paint to manipulate bitmaps is a joke, but that's what most
programmers have to do.
At my last job, the system administrator kept sending me automated spam
complaining that I was using more than ... get this ... 220 megabytes of hard
drive space on the server. I pointed out that given the price of hard drives
these days, the cost of this space was significantly less than the cost of the
toilet paper I used. Spending even 10 minutes cleaning up my directory would be
a fabulous waste of productivity.
Joel Spolsky, "The Joel Test: 12 Steps for Better Code"