I have already had two instances of naming characters that are names of people that have already had a varied degree of fame a few decades ago. For example: I wanted to use the name 'Slim Pickens' as nickname at one point, not knowing about Dr. Strangelove. The name just sounded perfect for the character, so I went out and google'd it (something I do with all my names now... just because I don't want to be called out for libel) and I found my guy riding a cotton-pickin' atom bomb. Damnit.
What are the common rules to name-usage? Can you use names as long as they are obvioulsy different? Do you just avoid these names at all costs?