Got muggy weather? Then look in your yard and you're likely to see these little fellows. They have many common names and many scientific names (Michael Kuo lists them under Conocybe apala; David Arora, Conocybe lactea), but they're fairly easy to identify: a white cone-shaped cap and a thin, very delicate stalk. Combine these features with muggy weather, and you've got the Milky Cone Cap, but not for long: I photographed this one mid-morning, and it was gone by noon.
These can also be called Pale Coneheads, which is what Conocybe apala means.