i was strolling around the small tuesday farmer's market at the ferry building today, and spotted these small green fruits, like large green kumquats. they were labeled as pineapple guava. the farmer told me to break one in half and eat the inside. when i broke it open, it revealed a custard colored soft interior that did indeed taste strongly of pineapple, but was definitely a guava. tart and acidic, but sweet and warm. the skin is edible but quite bitter.
i can't for the life of me remember the farmer or the stand, but he was selling pomegranates and persimmons, too. i guess that's not very helpful, either, since everyone else is selling persimmons as well. anyways keep an eye out for them. they're addictive.
I've seen them around the farmers' markets recently too. I have to say, though, being from Hawaii, that I enjoy the typical guava people think of which is the ones with pink meat inside with seeds and a soft but edible chewy yellow skin. I tried the pineapple guava out of curiosity and found them to be too tart for my tastes.