Here's just a few uses for salt:

Salt as a polish

By mixing salt and vinegar into a thick paste, it can be applied to brass silver and copper as a polish. Use a soft cloth to apply and buff, then rinse thoroughly in water and dry well.

Cleanups

This is one I learned as a kid working in a supermarket - for oil and egg spills, cover the area with salt - it's a lot easier to pick up.

Salt drain cleaner

Equal quantities of salt and hot water poured down a drain can help get rid of nasty smells and dissolve grease, plus help slow future buildup. This probably shouldn't be used in blackwater systems too often as it may upset the good bacteria that are crucial to breaking down solids.

Frost free windows and windscreens

Wipe down the inside of windows in your home and car with a sponge dipped in a saline solution, then dry. This will help prevent ice forming during freezing weather. Also, by rubbing a small cloth bag of moistend salt on your your car's windshield, this will help prevent ice from forming.

Scouring pots and pans

Pour rock salt onto greasy cookware before scouring to help cut through the grease

Removing tea and coffee stains

To remove tea and coffee stains on cups and decanters, sprinkle salt onto a sponge and use a circular motion when rubbing over the stains.

Sterilizing sponges

Kitchen sponges are the perfect breeding ground for all sorts of nasty bacteria. By soaking a sponge in a heavily saline solution, it will help kill these bacterial.

Pest deterrent

Where ants frequent, pour a line of salt to prevent them from crossing.

Earth friendly weed killer

A mix of 1 part salt to 3 parts boiling water can be poured directly onto weeds to kill them.

Mouthwash and gargle

I use this quite frequently - dissolve around a quarter teaspoon of salt into the equivalent of half a mouthful of warm water. Swish it around your mouth and gargle. I've also found this really helpful in dealing with toothaches.

Smelly cutting boards

A smelly cutting board simply means bacteria are present - and this is not only a whiffy problem, but a health issue. Bacteria are killed by salt, so by rubbing salt into your cutting board, let it sit for a little while and then rinse, your board will smell fresh and be bacteria-free!

Fire extinguisher

Keep a box of salt close at hand as an emergency fire extinguisher for grease fires. While it shouldn't replace a proper fire extinguisher, it makes for a good backup.

Iron cleaner

Over time, irons pick up bits of junk that cause them to stick when you iron your clothes. To remove the gunk buildup, sprinkle salt onto a sheet of paper and then run the iron over it. Ensure you use a shot of steam to clean the jets after doing this and also wipe down the plate with a damp cloth once it cools.

Preventing creasote buildup

If you use a wood burning stove or heater, soot and creosote can build up in the flue, reducing performance and also increasing the risk of a flue fire.  A handful of salt thrown on the flames occasionally will help loosen the soot.

Here's a particularly interesting tip I came across a few times - by adding a pinch of salt to  milk, it will keep for a lot longer without noticeably altering the taste!

This only just scratches the surface of the various uses for salt - there's so many, you could go through many pounds of it a year. One thing to bear in mind though - while plentiful and cheap; too much salt winding up in our waterways or even in your yard can damage the environment; so as with all things, use it in moderation.