What do I do to camouflage hairline cracks on my concrete porch?

You can try filling it in with some caulk. Here are some good tips:

http://www.ehow.com/how_4666756_repair-hide-small-concrete-cracks.html

This is not normal. Looks like stress crack from the corner. If there is a warranty get him back to fix it. You can try to fix it but they may get worse.

It is normal, nothing to be concerned about. I let those be as filling in sometimes brings attention to the minor surface cracks. Then you will be even more unhappy. If it really bothers you, you can always tile over the porch.

Go to Ikea and get some Runnen floor decking. They are wood tiles with plastic underneath so they easily snap together. Put those on top of your concrete porch. They are SOOOO stylish looking. You will really love the final results! Here is a link to them:

http://www.ikea.com/us/en/catalog/products/90234226/

(And no, I don't work for Ikea. I have these tiles on my front stoop and I just love them. They are perfect for solving your problem!)

It is normal. You cannot put a warranty on concrete. There is too many things that can affect the finishing of the concrete, weather conditions, the dryness/wetness of material when it was poured, ground movement or erosion and many other things. You can look into staining the concrete which will hide the cracks.

buy some two part epoxy with hardener..flatten into cracks and either paint or tile..if tile be sure to install fabric under tile then thinset to slab..stopped spider cracks, added value..Do not ignore..they get longer and wider with moisture

Tile over it or live with it, or rake out and fill with liquid cement.