This post on "coding horror" is a great example of this phenomenon, or more specifically, the comments are a great example. At least half of the comments are from people who are debating which of these two lines of code are better:
if (s == String.Empty)
if (s == "")
Here's my answer: It's not important!
It's easy to get dragged into these debates because we all have opinions (and the one form really is better!), and of course the more time is spent talking about the issue the more important it seems.
Here's my trick for killing these stupid debates: Let's list all the issues and problems that we are facing right now. Now, where does this issue rank on that list? Is it in the top 10? The top 100? The top 1000? Are we spending more time talking about this one minor issue than we are spending working on any of our top ten issues? (You don't necessarily have to make the list -- just suggest that it exists and then guess where on the list the issue appears)
Sometimes that works. Sometimes it brings a little perspective.
And yes, this misallocation of time (aka "worrying about dumb stuff") is probably a top 10 productivity killer.
Update: Here's a good link (via news.yc) which offers one explanation for why people often spend the most time on the least important issues:
Parkinson shows how you can go in to the board of directors and get approval for building a multi-million or even billion dollar atomic power plant, but if you want to build a bike shed you will be tangled up in endless discussions.
Parkinson explains that this is because an atomic plant is so vast, so expensive and so complicated that people cannot grasp it, and rather than try, they fall back on the assumption that somebody else checked all the details before it got this far. Richard P. Feynmann gives a couple of interesting, and very much to the point, examples relating to Los Alamos in his books.
A bike shed on the other hand. Anyone can build one of those over a weekend, and still have time to watch the game on TV. So no matter how well prepared, no matter how reasonable you are with your proposal, somebody will seize the chance to show that he is doing his job, that he is paying attention, that he is *here*.
Update Two: Wasting time is fine, and even inane discussions of the best way to compare empty strings can be interesting. My real point is this: if we are actually trying to get something done, then we need to kill this stuff, or it will kill productivity. If, on the other hand, we're ok being in time-wasting-mode, then silly debates are probably harmless enough. I picked on the blog comments above not because there is anything wrong with them per-se (what are blogs for, if not inane debate?), but because it reminded me a lot of the silly debates that I've seen on work mailing lists (where they do cause harm).