vegetable garden (namely Cats)? anythingthat won't contaminate the food

Glad you asked this one. I have had a problem lately too - seeds that were planted have been dug up by everyone elses' darn cats. A friend suggested plastic bottles, half filled with water, just laid on the ground in the area where they are digging. Have done this for 3 days and so far so good.....................Have also had childrens plastic windmills suggested so might try those too.

Pepper. The strongest pepper you can find, Lay around bourder once every two to three day for a week. No cats, no rabbits no dogs. It works

Paint ball gun does the trick, you won't kill them but will scare the crap out of them....

if the cats don't come around with people outside then use human hair.
i'm a hairstylist/cosmetology teacher and we have women (and men) come in for bags of hair for this purpose. they say it works.