It mainly depends what kind of gag gift you want to get and what relationship you have with that person. There are many "inappropriate" gag gifts at Spencers that you can pick up like a pen, or a pack of gum that actually shocks you. Or a funny t-shirt. You know the person better than anyone on wikianswers so maybe just go into Spencers and see what reminds you of them.
Sorry I just reread your question and the above answer is for if you wanted to buy someone a gag gift. However, If you wanted to submit a gag gift idea into Spencers for them to cell then I would recommend calling their 1-800 number which should be on their web page and ask someone.
There are many websites that have good gag gift ideas. One can get ideas from 'Spencer's', 'Stupid', 'Baron Bob' and 'PrankPlace'. One can buy gag gifts from them online.
Spencer's is a good store to find gag gifts.
A good and funny gift idea for your boss would be to purchase a gag gift that is appropriate for your line of work. You can even purchase something that has some relevance to any inside jokes you may have with your boss.
Spencer Gifts is a unique gift shop featuring products primarily aimed at adults in their twenties. Products include gag gifts, novelty shirts, licensed merchandise from video games and cartoons, pro-drug paraphernalia, and adult toys.
During the Christmas season gag gifts are plentiful. These can be purchased at novelty shops and gag gift stores. Some of these stores are The Prank Store and The Goofy Gift Shop.
You no longer can submit your own couch gags. All you can do now (as of 02|2013) is vote on the three finalists.
The cast of Gift of Gag - 1955 includes: Jackson Beck as Bluto Jack Mercer as Popeye Mae Questel as Olive Oyl
There IS no Gag Island, to get an idea of what I'm talking about, look at the Youtube Video: "Myth Busters"
CANE
get glass and brake it
Spencers has great novelty and gag gifts.
There is no official reason why someone would receive a rock as a wedding present. Perhaps the rock was a gag gift.