The
Albert Kahn Museum in Paris houses a fascinating collection of early colour photographs and b/w film from around 50 countries all over the globe, taken between 1910 and 1930. Only a limited selection of pictures can be found on the site, but it is nevertheless worth a visit. The actual museum even more so.
On a somewhat related note,
Paris 26 Gigapixels is simply intensely cool! If you can't visit Paris, then this is the best substitute I know of.
PS: the topic of this thread should be changed and it should be made a sticky for storing sites such as these.