Credit cards are handy to have, just never keep a balance and you will be fine
Using credit cards statistically results in spending 12-18% more than you spend with cash. It makes it painless to spend money. Paying with cash makes you feel like you are buying something and you are more cognizant over how much you are spending. (looks like catdude just beat me to it)
Do you negotiate a bargain when purchasing groceries, gas, or a restaurant bill?
As long as you pay your balance every month they give you free crap.
Not typically, but my discount also comes from spending that 15% less.
Also, having had my identity stolen and not really knowing where it happened, I quit giving restaurant workers my credit card to take out of my site long before I ever got rid of them all.
Even the most basic identity theft is no fun to deal with.