I love vinegar for cleaning hard-water built-up on chrome in the kitchen and bathrooms. I put it in a baggie and tape it on the shower head, for the faucets, I sprinkle baking soda, pour on the vinegar and let it bubble then wipe. Vinegar does an amazing job on glass shower doors with soap / scum build-up. For those I use a squeegee and be sure to open a window for ventilation.
I've also cleaned glass and mirrors, but you need to wipe with newspaper to eliminate the streaks. Since we don't get the paper anymore, I just use Windex for the most part.
My hardwood floors look fine with a vinegar cleaning, but I prefer the shine stuff from the floor store. (It's all natural too, but costs a lot more.)