I'm a dental assistant, the advice we give at the office is to go for a brisk walk, the increased blood flow helps remove the anesthetic from the area faster. Good luck!
Mine has usually worn off by the time I get home from the dentist (45 mins, max). Maybe I have a high Novocaine tolerance, because I never feel completely numb. I feel more tingly- I don't have pain during procedures, but I don't drool or accidentally bite the inside of my cheek. I can still feel things and move my mouth normally.