By this time of year, we've seen list after list of great Halloween costumes, not to mention the many cosplay galleries that appear all year long. Buried in those lists, there are some costumes that require you to think, because they aren't all that obvious. Some illustrate a concept instead of a character. Others bring to mind a common phrase or adage. And yet others signify a pun that will make you laugh -once you figure it out. Here are some of those wordplay costumes you might enjoy, in a list I posted at mental_floss.