Photos: Holiday tech gifts we don't recommend

4. Motorized toothbrush

Motorized toothbrushes have been around for a while. This one sold by Hammacher Schlemmer is even ultrasonic. You might be tempted to grab one of these for a family member as a holiday gift that would actually be useful--it seems like a logical choice.

But stuff like this just makes an awkward gift. You never know who will open one of these and take it as a subtle statement of "your breath smells bad." Likewise, some people, upon receiving exercise equipment, will take it to mean "you're fat." Or "your feet smell" for one of those, uh, foot smell-reducers, or "you have a drinking problem" for a personal breathalyzer. Best to steer clear of these unless you're really confident about how it'll be received. Heck, even a Roomba robot vacuum could be taken the wrong way by certain people--you know: "Not only are you a slob, but you're lazy, too."