I was/am one of those people who can distracted for a LONG time looking up a word in the dictionary. There's always some cool new word on the same page, and maybe that makes you wonder about a word in the definition so you have to look THAT up, and it just snowballs. Encyclopedias are just as bad (remember those?)
But the worst by far is the Internet. I found the post-it note video from a link about typefaces, which I found in a quiz about Helvetica vs. Ariel (check it out if you're a font geek like me!), which I found in a blog with instructions about making your own bows, which I found on a creative blog I check regularly.
And somehow, my floors never get vacuumed. I wonder why?
(And we're not even counting the time spent putting together the blog post with links!)