heh. Well, Portland Oregon is now the #1 per capita market for the Prius (meaning we may not sell the most in raw numbers, but we sell the most as a percentage of all cars sold,) so I see them all the time. Literally a dozen a day. (I drive for usually 3-4 hours around town each day, so I do have plenty of time to notice them.)
When my wife and I drove to her family in Nebraska for spring break, I saw only 2 after leaving Portland. One was in Boise, Idaho on the way back. The other was in the small town in Nebraska we were staying! (York, NE, for those that care.) The one in Nebraska also had Oregon plates! (I figure those Nebraskans must have thought that these mysterious 'Hybrids' came from Oregon, and that all Oregonians drove them, as it was also the only other car with Oregon plates we saw.)