Depending on the size of your yard and garden, you might find it easiest to feed the little stinkers and fill their bellies, rather than have them come closer to your patch in search of chow. Even if you're not actually trying to feed them, but rather birds and deer, you need to keep items such as bird feeders, bird baths, and salt blocks as far away from your garden as you can. (and your neighbor's for that matter) If the squirrels are too buys stuffing their mouths with peanuts, chances are they won't even notice your carrots.
Marigolds are nature's gift to gardeners. Not only are they hardy in hot weather, they drive away some furry critters, they also seem to get rid of pesky bugs, too. Plant marigolds around the perimeter of your garden. Fair warning: rabbits love marigolds. (You didn't think there was one fool proof get rid of all of them idea, did you? lol)
Human hair is another natural deterrent. Simply sprinkle a bit around your garden. If it's been extra windy, you may need to reapply. (which can be a little hard, depending on how much hair one has. Consider befriending a hair stylist at your local salon, who may help you out.)
Cayenne pepper can also be sprinkled around your garden, but if it rains - or you use a sprinkler - you're going to have to reapply it fairly often, and this could get costly.
Used cat litter can be sprinkled around the edge of your garden, but it could also attract male cats, so avoid this if possible. (Who wants sprayed on tomatoes? Not me!)
I've often heard that mothballs will keep critters away, but as these are poisonous, think twice about using them if you have any pets or small children of your own. Poison seems like an easy way to get rid of pests, but remember, those pets will wander off to die - and it could be your foundation they end up underneath. Just think of the smell on a 95 degree day. Poison doesn't sound - or smell - too good anymore, does it?
For me, I'm just going to stick to distracting the little stinkers at the opposite end of the garden with some dried corn.