I found an lost Android phone - is there a standard place on Android phones for owner information so I can contact the person who lost it?
Settings / About Phone / Status shows the device's phone number. Call it and leave a message. Maybe the owner will check their voicemail from home.
Or call people in the contact list, especially ones that show recent history. "Your buddy lost a phone..."
Or call the carrier and tell them you found the phone. They will be able to contact the phone's owner and relay your contact information.
There is now a standard place for Android phone users to set their owner information:
Menu -> Settings -> Security - > Owner Information
There is also a checkbox that makes this information show up on the lock screen.
There is an article about it at CNET with this useful screenshot: