That was a fun surprise.
When I was little, we used to find wild strawberries up in the mountains. My dad would take us camping fairly often and we'd climb around and eat the strawberries we would find, but they were like the end of your little finger (if your hand is small) and there wouldn't be more than four or five on a plant.
So this is not native, but it also came up in my yard without my expecting that it would!
strawberry blossom, March 2009: