For the past 18 months or so, our store has sold an As Seen On TV product called the ISlice, "The most useful tool you'll ever own." I hate it.
The little ear-shaped slicer has a tiny ceramic blade that too useless to cut anything big, but works well for cutting shapes out of paper, opening mail, and getting into difficult plastic packaging, like the stuff you must break through before you can use the ISlice. (Favorite customer joke: "What came first? The ISlice or the packaging?")
I hate the ISlice because it does not discourage the wasteful, exaggerated plastic packaging. Instead, it has made opening plastics "easy" and "fun." The product does work; I've tried it. I hate the idea, though, of this tiny blade floating around in homes, one use for one product, the tiny plastic thing for opening plastics. Also, because of the diminutive size of the ISlice, I imagine that it is quickly lost in many homes, thus leaving people unable to open all their gadgets and batteries and CDs without difficulty, tearing up junk drawers and pencil cans looking for that tiny tool they bought just for that situation.