If you wish to see Old faithful but aren’t planning to come to Yellowstone anytime soon, the park has a LIVE webcam that shows the Old Faithful eruption in real time. Today (9/27/12), the next predicted eruption is 1:45pm American Mountain Time. Link Below!
Old Faithful LIVE Camera: http://www.nps.gov/yell/
Photo Credit: Old Faithful Geyser at Sunset, Yellowstone National Park, 1920's NPS Historical Photograph
More info on Old Faithful: http://mms.nps.gov/yell/