This is a strange poll, it depends what country you are in, what country you are targeting. But at a guess, (I haven't actually worked it out ), but I would say the clicks are coming at the same rate the whole day. FFMG
I guess my site has international appeal, but because the bulk of the visitors come from USA, my peak is during the day (US time).
As far as gettting the most money per clicks--that seems to happen very Early in the morning. 12am - 3am PST - it is almost like the PPC get reset from the day before. But 4-9pm PST is where I make the most money the traffic comes rolling in at that time and I get a considerable amount more clicks. This has nothing to do with the PPC tho but traffic.
I believe 5 - 9 pm CST is when my website brings in the most money - because that's prime time for sites like mine.