Not WWII, but I like to go looking on Google Earth for important Civil war sites and locations. Can actually be pretty difficult in some locations, since rivers, roads and wooded areas are so different almost 150 years later. Modern photos look almost nothing like the way they were then.
Of course, I also went through and located all the 8th AAF bases from WWII that I was aware of a few years back, and a lot are still plainly evident from the air today.