From DailyKos via the Plank, which also has serious analysis. It's a detailed county-level map of primary results. What I find interesting: if a state border is visible on the map, that's because it's a home state for Obama (KS, IL) or Hillary (AR). The exception is Oklahoma, which is visible by default because it's sandwiched between two home states. Interestingly, the converse isn't true: the IL/WI and NY/PA borders are invisible, because they coincide with strong Obama and Clinton regions respectively. Since contiguous states generally did not have similar primary dates, this map is suggestive of how unimportant campaigning has been in this election.
I should stop posting maps.