Thanks Phil and Alex! I did at least see some awesome internet pictures! =)
And yes, it seems to make *no* sense and is at least harmful in one way evolution should care about - it was the leading cause of maternal mortality until the 1950s, when we found out how to replenish liquids through IV. Before that, the most extreme cases (hyperemis gravidarum) who can't keep anything down, food or liquid, would die of dehydration.
But, I do have to report that there seem to be reasons it's helpful evolutionarily too. From this press release
(I haven't actually read the study itself): "Our study, which tested theories and predictions about the nature of parent-offspring conflict in human pregnancy, shows that nausea and vomiting in pregnancy is beneficial by expelling such foods as meat and strong-tasting vegetables that historically and still may contain harmful toxins and microorganisms that could potentially sicken the woman and damage her fetus just when its organs are developing and are most vulnerable to chemicals," said Sherman, who is an expert in Darwinian medicine -- viewing diseases from an evolutionary perspective.
I can totally vouch for this nausea having me avoid meat and strong-tasting vegetables...