Peppers have the Progressive Pepper Corer Duo ($9.69), which is actually a set of two tools designed to core and seed peppers. The larger corer works on bell peppers while the smaller is for jalapenos.
I have to admit that most of the time I simply cut peppers in half and remove the core and seeds with a knife - because usually my next step is cutting the peppers into even smaller pieces. But there are times when it's desirable to leave the pepper whole - like when stuffed peppers are on the menu.
The same concept works for the jalapeno corer, but of course on a smaller scale. And, the big bonus for me, as a contact lens wearer, is that using the corer minimized right-hand contact with the peppers since I held the pepper with my left hand and my right hand held the corer at a safe distance from the pepper's interior.
The only problem I had with the jalapeno corer was with one radically bent pepper, but those with a gentle curve were fine. And I'm sure that trying to core that bent pepper with a knife would have been just as problematic.
While these are specifically marketed for use with peppers, there's no reason you couldn't use them for cutting holes in other fruits and vegetables, like tomatoes, melons, or banana cupcakes. (Wait ... banana cupcakes aren't a fruit?)
Since the corers are made from plastic, they'd be safer for kids to use, and great for adults who have knife-handling issues. They're dishwasher safe and nest together for storage.
While these aren't an essential kitchen item, they do make coring peppers a lot easier, so if stuffed peppers are often on the menu often or in large quantities, these could be handy to have. And then once you have them, you can start coring holes in your carrot muffins.