Neither of our places in NYC or Washington are big enough to put us out of earshot of the kid's crying, so we've never had a baby monitor. [Note to the various people whose emails about baby monitors I have inadvertently ended up ignoring the last month: apologies. It's not that I was ignoring you to hide my ignorance; I've just been swamped with work/kid/etc.]
Anyway, for this Christmas trip to the in-laws' house, where we knew we'd be staying in a separate guesthouse, we got what amounts to a disposable baby monitor, figuring if it lasted a week, it'd be fine.
The Safety 1st Crystal Clear Nursery Monitor is bare-bones basic, with two channels and one receiver that either plugs in or uses 9-volt batteries. There aren't any neighbors or cordless phones to contend with, so I have no idea about interference, but the Safety 1st has truly incredible sound pickup, and it worked great between buildings and across almost 100'.
It was so sensitive, it picked up otherwise inaudible motor noises from the nearby pool, and the kid's pacifier sucking sounded like a little wooden mallet. And as I just found out, it picked up the sound of me sneaking off to take a whizz--even though I'd closed the door and aimed for the side of the bowl, all quiet-like--and broadcast it back to the kitchen in the main house. So I scored major points with the 'rents on that one.
Buy the Safety 1st Crystal Clear Nursery Monitor [and Urination Detector] at Amazon for a mere $16.99 [amazon]
Baby monitors aren't really about hearing the kid cry. The whole point of crying is that you WILL hear it. Used effectively, the baby monitor let's you pre-empt the cry by hearing (and responding to) those subtler sounds that tell you she might end up crying.
It's easier to jump up and change the diaper of a sleeping kid when you hear a particularly squishy fart than it is to deal with getting her back to sleep after she wakes up hollering in discomfort.
In much the same way, I've grown fond of the video baby monitor system (by Sunny?) my brother gave me recently. Now if I wake up hearing a shuffle I take a peek at the screen. If the sound was the monkey kicking her blanket away, I know to fix it before she's cold, pissed off, and telling us about it.
Sure wish someone would come up with a more secure baby monitor, though. We've heard random traffic (900MHz cordless phones perhaps?) a few times, which means somebody has accidentally heard us to. The things are so sensitive that we're basically broadcasting our conversations to anyone inclined to listen.
We had a similar experience over the holidays. The twins were in weird sleep patterns and were falling asleep in all different rooms, so we were changing the normal configuration of our monitor. My wife and I were having some discussion about my parents and then realized that we had the microphone next to us and the receiver downstairs... next to my parents. Fortunately the power was off, but that could have ruined xmas. heh.
never really had a use for these. our babies have always slept with us in the same bed. my oldest now has her own room and bed and a monitor for her of course is not needed. restless nights? never had the experience, any fuss is detected instantly. of course when they are sick that's a whole different situation.
We have a monitor with lights. This is useful because our son is a very restless sleeper... he is sleeping, but not quietly (one of the reasons he was booted from our room and into his own within his first month). We keep the volume very low and the lights help us know when he is really awake and not just making his sleeping noises.
Of course, he is 14 months old now and we don't use the monitor unless we are at my in-laws' or my parents'.