When life gives you lemons, clean your bathroom. :D Simply slice a lemon in half and rub it on any hard water stains and rinse clean. Vinegar can also clean away chalk from hard water (I use it for the shower head)
Mr. Clean Magic Erasers: Creative Uses For These Household Cleaning Blocks That Truly Work Magic!
Toilet Cleaning Tip-sprinkle the inside of the bowl with baking soda then spray with vinegar. Let the foam work for a few minutes then scrub with a toilet brush. Spray down the whole toilet with vinegar and wipe clean
How to fake a clean house in 20 minutes. Over 25 tips, some that you probably wouldn't think of. Technically this is not really cleaning but an essential tutorial for emergency situations (like last-minute visitors).