Google the 50,000 year old spark plugs found in CA during the late 1960’s, it will blow your mind.......
Here is the link to a History Channel story on the spark plug, with photo’s starts at 4 minutes in, http://www.youtube.com/watch?v=ZR86JqKP8BQ&sf=Relevancy#1
It’s a hoax.
Coso artifact
http://en.wikipedia.org/wiki/Coso_artifact
OTOH, it’s still an interesting thing.
Ooparts: (Out of Place Artefacts)
http://www.ancient-wisdom.co.uk/ooparts.htm
Ancient rock “carved faces” found: Sign of lost race, or geological processes?
http://www.freerepublic.com/focus/news/1004461/posts
Walker ‘Stone Tools’ Weren’t Made By Humans, State Archaeologist Says
http://www.freerepublic.com/focus/news/1795757/posts