A few days back, bizzflip asked the following question:
What are you more likely to see in San Francisco, a UFO flying overhead or an available parking space near where you want to be?
As a proud inhabitant of SF, I'll tell you that I rated the difficulty of this question "easy"; but I now decided it was time to downgrade it to "trivial". Not only is a mysterious UFO Response Team fearlessly making sure the City remains a UFO-free environment, but they also began taking some of the few parking spots that were still available...
Mea Culpa, January 16th
Ooops coming too close to the Proton Packs laying in the trunk of that car must have interfered with my brainwaves; I should be downgraded, as the question went up from "easy" to "slightly tricky".