Oh, what does it take to see the former official residence of the Dalai Lamas?! If you are an average tourist you have to make a "reservation", by showing up a day before at 7:00 in the morning with your passport and passports of anyone else who's going to visit the Palace with you. Waiting untill 8:30 for the gates to open, then waitint till 9:30 for the reservation booth to open and then another hour and a half until it's your turn (since I only got there at 7:30, I was actually one of the last ppl to be let in that day). And this is just to book a time slot to see the Potala. Ours was at 2:30 pm the following day.