I love those glossy photographs that Life Magazine is famous for. Now the magazine has placed 10 million photographs on Google's servers. The photographs range from Margaret Bourke-White's harrowing depictions of the just-liberated concentration camps to Dorothea Lange's haunting photo of a migrant mother to pictures of men walking on the Moon.
One picture that I especially like is that of a parade on Pennsylvania Avenue in 1865.
On many of the photos, you need to click on the link labeled "View Full Size" in order to see the high resolution version.
You can start exploring here: http://images.google.com/hosted/life.
Another method is to search Google by and simply add "source:life" to any Google image search. That will limit the search to the LIFE photo archive. For example: genealogy source:life.
Even if you don't find exactly what your looking for there's lots of interesting pictures.
My thanks to Carla Bodette for letting me know about this valuable new resource.