Plenty of hype going on about Buzz Aldrin's comments about the "monolith" on the Mars moon Phobos (or more correctly, his comment "who put that there?"):
The 'monolith' has been known about some time, though Buzz's comments are sure to be replayed by alien-conspiracy theorists for the next century or so. The images of Phobos were taken by the Mars Global Surveyor in 1998, and discovery and discussion of the apparent anomaly occurred soon after.
An interesting analysis is this one by Lan Fleming, which looked at shadows and sun angle to come to the conclusion that the rock/alien anomaly is around 28 stories high and worthy of "serious investigation by NASA, even if they ultimately prove to be less unusual than they now appear to be". (Thanks to Martin for the heads-up)
Buzz is becoming a YouTube phenomenon, between this video and the other one of him punching a Moon-hoax believer...