On Saturday, July 21, 2012, I got a walk up permit (cancellation) for a day hike of the Mt Whitney trail for the following day, Sunday, July 22.
I showed up at the Lone Pine visitor center about 10:30 and checked for cancellations. They had no day hike cancellations available but said to get in the 11:00 am lottery. At 11:00 about 16 people drew numbers from a hat. These were both day and overnight hikers. The number drawing was for the order in which we went up to the permit counter and got served.
There were still NO day hike permits available when I got to the counter. The ranger told me to come back around 2:00 pm because that is when the computer kicks out more cancellations. I returned at 1:30 and there were 2 day hike permits available for the next day. My buddy and I were a party of 2 so it worked out perfectly.
Next day's hike went great.