The world is full of futile undertakings. There's not much point, for instance, in attempting to herd cats, squeeze water from a stone, or nail Jell-O to a tree. And, while there may be more than one way to skin said cats, I can tell you from personal experience that skinning eels can drive a person mad with frustration. But of all the kitchen tasks that make me want to pound my head against the counter, dicing room-temp bacon has to be one of the worst.
Slippery and squidgy when even slightly warm, the wide striations of fat in bacon, pancetta, salt pork, and fatback slither and squirm beneath the blade as you try to slice them. A razor-sharp knife can just get the job done, so long as you work fast and it stays cold, but dillydally at all and you're more likely to end up with a ragged pile of torn, shredded, mashed, and smashed bits than the nice pile of even cuts you were aiming for.
This happens because animal fats are a complex mixture of different saturated and unsaturated fats, and thus melt over a wide temperature range. While you'd have to heat pork fat to well over 100°F (38°C) to fully render it, some of its components will begin to liquefy even at room temperature. Touch it with your fingers as you dice it and your body heat warms it up even more, partially melting it and creating a slippery texture. With each passing second, the fat becomes more and more difficult to work with.
Of course, as with many things, the solution is obvious: Keep it cold. What may be less obvious is just how cold.
You have a couple of choices here. You could, for instance, just keep all your fatty pork products, like bacon and pancetta, well wrapped in the freezer at all times. Kenji, for instance, tells me that he always keeps his sliced bacon in the freezer, cutting off only what he needs from the frozen-together strips. (They inevitably stick together when frozen, so attempting to peel off individual strips will just get you a bunch of broken and torn shards.) This method can be more difficult with slab bacon and other solid cuts, like fatback, which freeze so hard through the center that trying to cut them becomes like trying to push a knife through a block of ice.
You can still make it work by simply tossing the frozen hunk of fatty pork on an aluminum baking sheet for several minutes, until it's soft enough to cut. As we've shown before, the excellent conductivity of aluminum rapidly transfers the room's heat into the frozen food sitting on it.
The other option, which is often what I do, is to keep the pork cuts in your fridge and just toss them in the freezer for 10 to 15 minutes to give them a deep chill before slicing. The goal, after all, isn't to freeze the fat fully, but to drop the temperature enough that it becomes workably solid. As the fat gets colder, it hardens more, giving you something firm to slide your knife through.
That, as they say, is as easy as apple pie, and you, instead of being frustrated, will be as happy as a pig in...(not the freezer).