How do I find out about US servicemen who were here during the war?
Most US service records were stored in St Louis. There was a fire which was contained, but the sprinklers still managed to ruin 80% of the records. You can write or apply online using this link, and you may be one of the lucky 20%. If the records exist, they are provided for free. It may take four or five months, however.
The draft records were kept separately and have been preserved. They give basic information such as date of birth, home address, level of education and civilian occupation for those men who registered for the draft. You can access them at the US National Archives and Records Administration, using this link.
For a complete guide to finding such information, read this six page document from NARA.
How do I find out about Australian service personnel?
Department of Veterans Affairs Nominal Roll contains basic information about every one who served.
Full service records are available through the National Archives. Some are online, some have to be ordered.
For a comprehensive guide to finding information, visit this page at the National Archives of Australia.
Why doesn't his hat look like other general's hats?
MacArthur came out from Corregidor wearing the distinctive Field Marshal of the Philippine Army hat he had designed for himself. One of the first things he did in Melbourne was have it cleaned and blocked. He continued to wear it until he redeemed his pledge, "I shall return", as a visual reminder of the duty he felt the US had to its territory, the Philippines.