Google hosts Life photo archive

The photographic archives of Life magazine, dating back to the 1750's,  are now available via Google Image Search.

This is an incredible resource presenting millions of fascinating photographs many of which have not been published previously.  Currently only 20% of the collection is online but this is being added to all the time.

For further information see here and here.

Warning : don't go browsing until you have a couple of hours to spare, this stuff is strangely addictive!