Detective Sleepover--For my son's 9th birthday we had a Detective Themed Party.  The cake was decorated in the shape of "Question Mark" to go with the "Mystery" of detective work.  We played many games with a detective spin, Scavenger hunt outside (include item you know they won't find such as a purple duck, a ice-cream frog, to make the list more fun)...another game was Magazine Clue Hunt, I went through old an old magazine. and found 1 odd picture from each magazine (a ad of a man with a snake tongue, a football player holding a basketball etc.) then I put them on a list and gave copies to each boy, they searched the magazines and put down the page # & title of the an old magazine were they found it--first one done won a prize. All game prizes were enclosed in Brown "Confidential" Envelopes marked "Top Secret"...each prize packet contained 1 detective tool (magnifying glasses, flashlights, tape measurers). The party favors when they left were also packaged in "Top Secret" envelopes and included other misc. items such as ID Wallets with their own detective badges printed...."Detective Jake Kirby, ACME Detective Agency" for pretend play.