Clichés

After reading Ron Wallace's "Blessings" in Chp. 10, I was wondering what everyone thought about the use of cliches...when do you think they are acceptable to use in writing? Are they simply used because they are widely known? Or do we use them because we do not put forth the effort to provide original insights? Personally, I know that I use them in my speech, but not so much in my writing...even though I did find Wallace's twist on using cliches pretty entertaining.