I do, but usually not for long. My older kids drop things on the floor or leave a small chokable toys around from time to time. My youngest has an uncanny way of finding them ;)
Most of the time she just crawls my way after a few minutes anyway.
Meghan : Kayla~ 10/19/04 Jack~ 5/27/07
It's funny, since I posted this it's gotten to the point where I can't let him play alone as much because he's really starting to get into trouble. The other day he was upstairs and he unrolled the entire roll of TP and threw EVERYthing into the tub. Yesterday he was playing in the kitchen - I was in the living room and I went in and he's gone. Turns out he figured out how to push open the screen door and was on the (gated-in) porch, looking like this:
Me (40) DH (49) daring DD (9) and darling DS - almost THREE! (born June 25, 2010 in an amazing, unplanned
I babysat years ago for a family who did this, and always knew I wanted to do it with my own kids- we completely baby-proofed the living room and have it gated in, so that if I have to step out I have no concerns. I don't do it a lot, just because my child doesn't like to let me out of his line of vision, and honestly there's not much for me to do elsewhere. But this morning, for example, he woke up around 3am and would not go back to sleep- so by 4 I just brought him down, plopped him on the floor, and dozed on the couch. Of course it wasn't quality sleep and I was pretty aware of what he was doing. but I was not ready to be any more awake than that.
I think I'd stay in earshot, though- I'll run around the house and gather laundry, but I wouldn't go upstairs and shower while he was in there.
I do let my 14-mo-old play alone (mostly bc, like others have said, I have another child, have to cook dinner etc, and have no choice) -- but I really feel like there's no such thing as babyproof. He wants to crawl up/ on everything, and eat everything.... I feel like I constantly discover him doing something not quite safe. Yesterday he climbed up on the baseboard heater and was right in front of an open window - he climbed up a bathroom stool and was basically hanging on the sink - he's crawled into the bathroom when the tub was on for my older child..... this child is everywhere. I find him w random objects in his mouth all the time. This is with me thinking my house is babyproof. So yeah, of course we all do it, but I think it's important to keep a close eye on them too.