When you live in an apartment or a condo not only do you have to put up with noisy neighbors, you also have to deal with their smells sneaking into your home via the hallway. A draft blocker is one way to seal off the crack at the bottom of your front door, but those always seem to be in the way. So the Door Filter, which attaches to the bottom and rides along whenever your front door's opened and closed, seems like a far better one.
It doesn't completely block drafts, though, because you actually want your building's ventilation system to do its thing and keep a constant supply of fresh air pumped into the hallways. The problem is that fresh air isn't always so fresh, especially if your neighbors fancy themselves amateur chefs, or enjoy kicking back around 4:20 every day.
So the Door Filter seals off the crack at the bottom of your front door, but channels all of the air from the hallway through its replaceable dense particulate filter that traps odors, pests, and allergens, and prevents them from continuing on into your apartment. Think of it as kind of like a front door Brita that ensures you don't have to smell what your neighbors are cooking and/or smoking every night.
At just $50 (plus $13 whenever you need to change the filter) it's not unreasonably priced, either, and you don't have to worry about swapping batteries or running power since it's completely passive. Installation is as easy as screwing it to the bottom of your door at the right height to make an adequate seal, and there's an optional kit that includes a sweep so the Door Filter works effectively on uneven floors too.
And if it works so well on your front door, just imagine what it could do for your bathroom, especially if you live with roommates. [Door Filter]