Both AE Brain and Orbis-Quintus have posted about Homo Sapiens's relatively recent (and maybe continuing) coexistence with other hominid species. Alan is pairing genomic evidence for a recent (relative to chimpanzee) constriction in the H. Sapiens lineage with news items about the global impact of a supervolcano. Not only H. Sapiens, but also Neanderthals and the hobbits came through the last supervolcano eruption. Would their DNA show a comparable bottleneck?
Badgerminor links to the pursuit of the Dwendi, a "little goblin" in the forests of Belize. I am taking the bigfoot/yeti class of stories a bit more seriously with the discovery of the hobbit fossils (which were, after all, only 20,000 years old.) The limit on speculation about contemporary hominid diversity is the global ability of H. Sapiens to eliminate even indirect niche competitors. Wolves are almost gone, because they sometimes eat our sheep. Would bigfoot stand a chance?
UPDATE: Via Syaffollee, the long-suspected cryptid monster-under-the-bed, P. Umbris. We have several in our house, who additionally seem to wet beds.