http://engineerdog.com/2015/03/15/engineers-beware-the-ultimate-productivity-killer-nerd-sniping/

Beware nerd sniping.  The problem is that the things can come out from anywhere. That vendor’s website.  The casual comment by a coworker.  The misguideded web search.  If you think that the ideas are worth pursuing but not immediately relevant to what you are doing, bookmark the website, write it down in your idea book, spend half an hour of so doing the beginning follow up and then move on.  You don’t have to keep absolute focus on the task at hand, but you shouldn’t allow yourself to lose track either.

Also beware the project diverter.  You know that thing that says “I can do it cheaper and better”  I had a project get eaten by that last year.  Unfortunately the diversion turned out to be necessary in the end.  So I need now to design and build the diversion as well as do the project.  All of which will show up here.