Stupid grocery store tricks
When I worked in the grocery store, I would superglue change to the floor in our back room. Most employees came through our back room to get to the break room, so this supplied me with a continuous parade of people that would try to pick up the change.
I did this on the sales floor a few times, too. I had to quit after I watched a guy spend 5 minutes on his hands and knees trying to pry a quarter off the floor with his car keys.
I also used the old fishing line and dollar bill trick with much success.
One that I got hit with was tasting a persimmon. A buddy cut up two persimmons and put pieces of them on a tray. He called a bunch of us over and told us to try them. Naturally, noone wanted to try it (we were all a little distrustful of events like this). The guy quickly grabbed the only piece he had cut from the ripe persimmon and ate it. We didn't know he'd prepared the plate this way, so assuming it was safe, we all grabbed a piece and ate it. I don't know that I can accurately describe the taste of a green persimmon, but I remember my mouth drying out and feeling like I'd just eaten talcum powder.
Another produce specific trick was with hot peppers. Habaneros, jalapenos, finger hots - they all work. One thing we'd do was cut one open and squeeze a little of the juice onto the end of a straw or around the rim of a cup. Or, better yet, instead of Cherry Coke, or Coke with lemon or lime, you can have Habanero Coke.
We used to phone prank coworkers a lot, too. One of our favorites was to call from the floral department phone (the floral dept was part of produce and had it's own outside line - you could call another store line without a blinking light on the recipients phone alerting them that the call may be coming from inside). We'd call the liquor store guy a lot. A buddy of mine was good at impressions and voices, so he'd call up all the time and ask stupid questions or try to talk the guy into doing stuff for him. He called once and asked if the Mad Dog 20/20 gift set was available at the store (he described it as a bottle of Mad Dog 20/20 and a jar of vaseline in a lovely collector's box). Or once, he got the guy to agree to take food stamps for cheap wine. This guy's lifelong dream was to become a wrestler. He even had a character made in preparation. He wanted to be Nightmare, the Battle Master - he would study other wrestlers and then use their own moves to beat them. We'd call him up on his speaker phone via the intercom and challenge him to 'a can of corn battle royale on aisle 3'.
One of my managers (he looked and sounded like a cross between Abraham Lincoln and Jed Clampett) favorite things to do to me was about an hour after he left for the day, he'd call me at the store. He'd say, "Hey bubba, I got someone here that wants to talk to you..." and then he'd pop open a beer right next to the phone. He did that to me about once a week. There was one occasion when I worked the early morning shift and he had to come in for the afternoon. I took a lot of pleasure in calling him after I went home and reversing the roles.