If you have snails and slugs invading your garden, then stale beer will help get rid of them. Simply bury a clean container, like a margarine tub, to ground level and pour in the beer. The smell will attract the snails and slugs and they will fall in but can't get out so drown in the liquid. Simply dispose of the snails afterwards.
Also if you have brown patches in your lawn, a dose of beer poured over these patches will turn the lawn greener after a week, as the beer is high in nutrients for the soil.
Use the beer as a conditioner on your hair. Shampoo as normal then rub the beer in your hair and rinse off. The vitamins in the beer help feed your hair.
You can use beer to clean up inside your house as an alternative to chemicals. Use on stubborn tea and coffee stains on your carpet, by dousing the beer and blotting the stain up.
Try polishing your pots and gold jewellery or on wood furniture by soaking a cloth in the beer and rubbing away.
If you want to attract butterflies to your garden, then try mixing a can of stale beer with sugar or fruit juice and an overripe banana. Then spread it where you want to attract the butterflies.