Citrasolve

White vinegar, water and baking soda will clean almost anything. I use white vinegar and water in a spray bottle to clean mirrors/windows, works great.

I always have Clorox wipes around, although I'm starting to buy Method wipes instead.

For wood floors, Mop & Glo (with water) in the blue bottle. It gives the wood some polish, and they stay MUCH cleaner.

I've also heard milk for ballpoint ink stains. I did get ballpoint ink out of a cotton quilt once with Shout wipes. Not sure if they'd work on leather.

And, for my dog's accidents, Nature's Miracle.

Meyer's cleaning solution smells awesome....like roses. I use it all the time all over the house. It's highly concentrated also, so it lasts forever.

Okay, I did not read all of the posts, but alcohol cleans the ink, don't use hair spray with alcohol, just use the alcohol.
Once the ink is out you can moisten/treat the couch with leather cleaner/moisturizer.

I have worked with leather a lot. The dye of the leather might leach out a little, but it will be less noticeable than the ink. Hairspray will do the same thing only leave it all sticky.
Aquanet has silicon in it to seal out the water.

Anyone have good ideas for cleaning granite? I hate my black granite counters, especially in the bathroom. I use method 'daily granite' sometimes to clean it besides the home depot granite cleaner, but the white hard water stains are driving me crazy!!

Mean Green cleaner is good. I use it for cleaning everything in the bathroom. Also use it in the kitchen on the counter and around the faucet.

http://www.deerso.com/Mean-Green-Cleaner-P26888C0.aspx

Another place I found to use Mr. Clean Magic Eraser is for cleaning the refrigerator.

I use plain water to wipe down mirrors. no streaks, no fumes!